Thread Number: 79816  /  Tag: Ranges, Stoves, Ovens
Stoves without thermostats
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Post# 1037123   7/4/2019 at 12:17 by chetlaham (United States)        

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Has a stove without a thermostat ever existed? One where the temperature of the stove is controlled by varying the intensity of the heating elements?

I know in the USSR cooktops achieved varying temperatures by putting the elements in series/parallel or switching sets in and out instead of an infinite cycling switch- but has this ever been done with ovens?

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Post# 1037124 , Reply# 1   7/4/2019 at 12:29 by LowEfficiency (Iowa)        

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>> Has a stove without a thermostat ever existed? One where the temperature of the stove
>> is controlled by varying the intensity of the heating elements?

There sure was, and they were quite popular!

You had your choice of 100W, 75W, 60W, etc for the elements, and they sold replacements in various wattages at most hardware stores.


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Post# 1037127 , Reply# 2   7/4/2019 at 13:07 by Tomturbomatic (Beltsville, MD)        

Early gas ovens did not have thermostats; the cook turned down the flame. Magic Chef was among the first with the Big Red Wheel oven regulator.

Westinghouse ranges in the 1920s had a non cycling circuit breaker type of control. The desired temperature was set on one side of the scale of the control and the heaters were switched on. When the red pointer on the opposite side of the scale reached the arrow at the set point, the current snapped off. The door was opened, the food put in and the door closed. The breaker was reset and the current came back on. The cook had to pay close attention to the oven while baking, but it did provide controlled heat. The insulation helped to hold the temperature steady so a glance at the red arrow told the cook when to reset the breaker. I saw this range at the John and Mabel Ringling home in Sarasota. It was next to two large gas ranges that were probably used for banquets in the winter when the circus was home. The ovens on those had three linear burners with valves at floor level that could be adjusted to regulate the oven heat. The Westinghouse was probably a God-send in the summer heat, even with the breeze off the Gulf.

Post# 1037129 , Reply# 3   7/4/2019 at 13:21 by fan-of-fans (Florida)        

Didn't some of the early legged GE/Hotpoint ranges have a 3 heat setting switch for the oven, along with a temperature gauge?

I'd like to visit the Ringling mansion. I have been to the museum and grounds but we did not get to go in the home.

Post# 1037135 , Reply# 4   7/4/2019 at 13:53 by mrboilwash (Munich,Germany)        

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We`ve had them too. There were usually two separate rotary switches (0-1-2-3) one for top and one for bottom heat.
One of my older cookbooks from 1953 mentioned them as oldfashioned, but a 1963 baking book still gave directions on how to use them.
Usually both top and bottom was preheated for 10 min on "3", then you turned down the top heat to "1" or "2" but left bottom heat on a full "3".

They were called "Schalterbacköfen" (switch stoves) in Germany. Interestingly Google only comes up with Backofen Schalter which means oven switches.
It`s amazing you get 10,000 hits of switches but nada on those long forgotten electric stoves, but we`ve had a similar situation on syndets and hybrids as well some time ago...

Post# 1037136 , Reply# 5   7/4/2019 at 13:53 by chetlaham (United States)        
Easy Bake

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Those were nice, and still are!

Gas stoves- I've heard of those- neat and simple.

Hotpoint- I'm really curious of those existed!

Post# 1037138 , Reply# 6   7/4/2019 at 13:57 by chetlaham (United States)        

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Tell me more about these stoves! :)

I've been thinking of designing such a stove- one where a selector switch governs the temp.

Post# 1037140 , Reply# 7   7/4/2019 at 14:04 by fan-of-fans (Florida)        

This model has the three heat switches for the upper and lower elements, but I guess it is a thermostat on the side of the oven. Also those burners are odd. Anyone know what kind those are?

This unit is similar but it has Bake, Broil and Preheat settings with one knob instead, and the same thermostat on the side. Strange the burners on this one too are Chromalox? Thought the Calrod elements were Hotpoint's trademark, so fact it doesn't have them is odd to me.

Post# 1037143 , Reply# 8   7/4/2019 at 14:19 by chetlaham (United States)        
Look what I found

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Anyone know what stove this applies to? It looks like everything is switch controlled.

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Post# 1037144 , Reply# 9   7/4/2019 at 14:29 by thomasortega (We have a famous sign, earthquakes, bushfires and weed)        

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Post# 1037145 , Reply# 10   7/4/2019 at 14:31 by thomasortega (We have a famous sign, earthquakes, bushfires and weed)        

In Brazil, until today many stoves (actually most of the models on the market right now) don't have thermostats.

I mean, gas stoves, not electric

The flame is modulated and, believe it or not, they can be very accurate.

Post# 1037146 , Reply# 11   7/4/2019 at 14:45 by mrboilwash (Munich,Germany)        

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Chetlaham, wish I could tell you more but unfortunately have never had a chance to use one of those in person.

There is a museum in Hamburg I visited last year which is run by very nice people who seem to live for vintage appliances just like us on AW.
I could imagine they might be helpful on specific questions if you get in touch with them.


This post was last edited 07/04/2019 at 15:11
Post# 1037147 , Reply# 12   7/4/2019 at 14:59 by chetlaham (United States)        

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If it works for gas, I guess it could work for electric.

Post# 1037148 , Reply# 13   7/4/2019 at 15:05 by chetlaham (United States)        

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Another fixed temp, but for the burner only. I really want to try this for a stove:

Post# 1037153 , Reply# 14   7/4/2019 at 16:05 by henene4 (Germany)        
Electrum Hamburg

Gonna have to make a sunday expedition there since I can get to Hamburg for free on my student ticket.

Fun fact: Many induction cooktops do not have any thermal control besides the usual safety guards and just cycle and\or vary power.
On both the IKEA branded probably Whirlpool made and the BSH induction cooktop we had on the lower 2/3 of the power scale they would cycle their lowest power modulation (you can audibly hear the system cycling on and off) while above that the continous power would increase.

On ovens I know that some ovens broilers were not temperature guided, but that was more lower end models.

Also, to this day, many gas ovens over here do not have temperatures per se but settings from 1 through 7 or 8.
And obviously ovens without electric igniter or pilot light could not cycle.

And on the modern side of things I heared rumors that the eco bake settings on new ovens often have a mix of time and temperature based heating.

Post# 1037159 , Reply# 15   7/4/2019 at 18:27 by combo52 (Beltsville,Md)        
Reply # 8

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Is a GE and it has a thermostat.


It would be easy to take any electric range and use two infinite switches, one for the broiler element and one for the bake element and control the heat manually, but why brother. 


I can't believe that any serious oven in Brazil today does not have a thermostat, it would simply be too dangerous and take way too much attention to cook in.


I guess the only good thing about not having a thermostat is every oven would be self-cleaning, LOL


John L.

Post# 1037161 , Reply# 16   7/4/2019 at 18:46 by chetlaham (United States)        

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Big thanks! Is the thermostat adjustable, fixed or a high limit?

Self cleaning- perhaps- but the idea is that on the highest setting the heating elements would only output enough heat such that it would equal the heat loss at say 450*F. Same for the lower settings.

Down side would be preheating time- which honestly I don't know how to calculate- but would imagine take some time.

The prospect of an oven without a stat if very elegant and beautiful IMO. I want to build one if I had the ability to do so- could tinker around with a range and a variac come time.

Post# 1037162 , Reply# 17   7/4/2019 at 19:45 by Tomturbomatic (Beltsville, MD)        

Chetlaham, Your lack of knowledge about ranges and wiring diagrams is painful. We have explained to you about oven thermostats and gas ovens without thermostats, but you either don't read or don't comprehend and have led this thread on a goose chase. I think you might have been confused by the oven switches for the top and bottom elements that allow a cook to vary the intensity of the heat, but not the temperature, so that if the oven was full of pans of food the pans right under the top element would not be burned because it could be either turned off completely or operated at a minimum input.

You say that you would like to try the control in #13. It is not an oven control. There is nothing special about it. Most GE and Hotpoint ranges had the 5 heat switches for the surface units and, while they did not look the same, early Westinghouse & Frigidaire ranges had them, too, but you jumped the track from talking about ovens without thermostats to surface unit switches that allow a certain fixed wattage input without the need for thermostats.

Henne, those numbers from 1 through 7 are known as gas marks and they correspond to oven temperatures. You will see them used in British cookbooks.

Post# 1037164 , Reply# 18   7/4/2019 at 20:03 by chetlaham (United States)        

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"Chetlaham, Your lack of knowledge about ranges and wiring diagrams is painful."

Ok, so which part is that which triggered you?

"We have explained to you about oven thermostats and gas ovens without thermostats, but you either don't read or don't comprehend and have led this thread on a goose chase. I think you might have been confused by the oven switches for the top and bottom elements that allow a cook to vary the intensity of the heat, but not the temperature, so that if the oven was full of pans of food the pans right under the top element would not be burned because it could be either turned off completely or operated at a minimum input."

And what have I said the leads you to think I do not comprehend? TC 80 thermo- how do I know TC does not mean thermal cutout as in a high limit? I've never seen one of these ranges in person nor do I know anything about them beyond what has been stated thus far hence why I am asking about them.

Post# 1037166 , Reply# 19   7/4/2019 at 20:10 by chetlaham (United States)        

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"You say that you would like to try the control in #13. It is not an oven control."

Of course!

Its offensive for you to think that I don't know its for surface unit.

"There is nothing special about it. Most GE and Hotpoint ranges had the 5 heat switches for the surface units and, while they did not look the same, early Westinghouse & Frigidaire ranges had them, too, but you jumped the track from talking about ovens without thermostats to surface unit switches that allow a certain fixed wattage input without the need for thermostats."

Its not a jump track- I want to apply the same concept to an oven- which is what I have been imagining all along. Have 3 or 4 heating elements inside the oven and using various series/parallel/on/off combinations to achieve multiple temperature options. If it works for a surface burner, why not an oven.

Post# 1037169 , Reply# 20   7/4/2019 at 22:26 by LowEfficiency (Iowa)        

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>> If it works for a surface burner, why not an oven.

You absolutely could make what you're describing for an oven, and you absolutely could cook food in that oven.
But using it would be a miserable process.

Surface burners have controls which vary their heat output, but only as a percentage of their maximum output, not as a temperature setting. They can do this because the thermostat in the system is YOU, the cook!

Surface burner controls are like the accelerator pedal on your car. Let off the pedal and you get your idling engine's minimum output. Floor it and you get your engine's maximum output. But no position of pressing the pedal strictly correlates with vehicle speed - it is up to the driver to vary the pedal input to accelerate to, and maintain, their target speed. Want to go 40 mph on flat ground? It might take a medium amount of pedal. Want to go 40mph up a steep mountain incline? It might take most of the pedal's throw and significant laboring of the engine to do so. Want to go 40mph DOWN a steep incline? You may need to let off the pedal entirely.

The human driver adjusts the power input to what is necessary, just as you do for a pan cooking pancakes, or a huge pot boiling water. On a vehicle, the cruise control is a good equivalent for the thermostat - set the cruise control to 40mph, and it throttles the engine as necessary to maintain your speed regardless of the conditions.

For an oven, you could do the equivalent manual process, having multiple taps of fixed power level inputs. But to obtain your target temperature will take a lot of waiting, monitoring, and adjusting. It becomes very easy to overshoot and burn your pie, or undershoot and change the way your meal cooks. Recipe guidance is based on a measurable time+temperature quantity - take away the stability of the temperature, and the cook time also varies, meaning you have more guesswork and checking to see if things are actually done. And you toss repeatability out the window - a pizza baked tomorrow will take a different amount of time than your pizza did today, just because of the temperature swings, heat soak, etc. Recipe books would be a disaster, as there would be no consistency between oven brands or models, let alone adjustments for the local climate or other factors that influence the temperature inside the oven. And the system becomes extremely sensitive to interference, such as heat loss when opening the oven door.

Doesn't sound very fun, does it?

Post# 1037171 , Reply# 21   7/4/2019 at 22:53 by chetlaham (United States)        

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I fully agree with everything you said. Preheating would take a long time too, which would be a downfall.

Though for me its fun enough to try.

Post# 1037172 , Reply# 22   7/4/2019 at 23:15 by LowEfficiency (Iowa)        

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Theoretically, you could preheat in an identical amount of time. With or without a thermostat, the preheating would just be turning everything on full power and waiting until the desired temperature is reached, then turning it down to a reasonable power level to maintain that temp.

But you would have to be paying attention, as a failure to change the setting would be equivalent to starting a self-clean operation!

Post# 1037204 , Reply# 23   7/5/2019 at 03:04 by mrboilwash (Munich,Germany)        

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Not sure if such a stove would meet today`s safety standards, maybe if a thermal fuse was part of the system and I wonder what the benefits might be as thermostats aren`t that expensive anymore.
On the other hand I don`t think a Schalterbackofen ever reached temperatures even close to self cleaning even if someone forgot to turn it down.
Suppose overall maximum Wattage was way too low. The suggested 10 min preheating time rather seems like a bit of a prewarming. Guess you just had too put the food in early because of economical reasons, in other words to save on current.
Just think of early electric clothes irons, they were more in the 300 W range if at all vs. about 1000 W when thermostats became the norm.

Post# 1037205 , Reply# 24   7/5/2019 at 05:17 by kimball455 (Cape May, NJ)        

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When I got my house it had a Magic Chef stove. There was no thermostat on the over, you varied the flame just as like surface burner. I got quite good with temp control. Use that stove for years until the oven interior fell apart from rust and age.

Post# 1037207 , Reply# 25   7/5/2019 at 06:19 by combo52 (Beltsville,Md)        
Reply #15

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If the oven was designed to be able to only reach about 450 F it would be near useless, you would never be able to do even simple things like baking cookies where you need nearly 400F and you are oping and closing the door at least every 5 minutes as you rotate two sheets of cookies.


And when you do a large roast or turkey it might even be dangerous because the food might not cook quickly enough to stay safe.


OK I'll bite, what is the point of building an oven without automatic heat control, it seems a little building a car without brakes or steering, it might be beautifully simple but about useless.


John L.

Post# 1037221 , Reply# 26   7/5/2019 at 11:12 by chetlaham (United States)        

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@Mrboilwash, that is the plan. The total oven wattage on high would be such that the oven could not overheat.

Combo52: You have a point, opening the door would cause a very big drop in temperature which would take a much longer time to recover from. Also large foods as Turkeys will probably pull the temp down substantially. Though as you know I am curious to see the severity in reality.

An oven without a thermostat would have the pros of being more reliable, no swinging temperatures once stabilized (Breville has built its business on this and yes I am aware they use an electronic thermostat) and possibly being cheaper. PRC (Peoples Republic of China) is already building warmers and compact ovens with fixed PTC resistors- a somewhat similar concept.

And to the person who liked reply #17- life is short to be filled with so much malcontent. Let people imagine, let others try something new even if it might fail in the end.

Post# 1037226 , Reply# 27   7/5/2019 at 12:56 by mrboilwash (Munich,Germany)        

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Did a little research on Ebay and there are still some of these stoves to be found. Looks like they made it well into the 1950`s just because they were cheaper to buy than a "Reglerbackofen" (one with an infinite thermostat).

An AEG model has a picture of a somewhat corroded rating plate where the top element is rated 600 and the bottom element is 500 Watts if I`m not mistaken.
Those German pre and postwar stoves were not turkey size of course, but a roasted duck or goose could be made in a reasonable time.
The most powerful one I could find has 1500 Watts for both elements together, which is almost as much as one of the "weaker" thermostat controlled ones of that time.

It may also be worth to mention that an electric stove that can only be controlled over 11 possible combinations of top and bottom heats instead of a thermostat is still a godsend over a wood or coal fired stove.

CLICK HERE TO GO TO mrboilwash's LINK on eBay

Post# 1037228 , Reply# 28   7/5/2019 at 13:31 by chetlaham (United States)        

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Mr. Boilwash, thank you! This is immensely inspirational. The more I think about it the more I smittened by it.

And yes, I am not surprised at all. The elements will have to be of lower power to prevent the oven from going over say 500-600*F.

Post# 1037231 , Reply# 29   7/5/2019 at 13:54 by kenwashesmonday (Haledon, NJ)        

fan-of-fans wrote:

"This model has the three heat switches for the upper and lower elements, but I guess it is a thermostat on the side of the oven" 



I'm thinking that may be a simple thermometer.  The cook would watch the thermometer and manipulates the switches accordingly.


I believe that Hotpoint came out with the Calrod heating element in the late 1920s.  Is it possible that these ranges are older than that?



Post# 1037240 , Reply# 30   7/5/2019 at 15:48 by chetlaham (United States)        

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I want a wiring diagram to one of those ovens, either the Hotpoint or the German version.

And yes, I also suspect that may be a state... hoping that it is LOL.

Post# 1037243 , Reply# 31   7/5/2019 at 16:34 by mrboilwash (Munich,Germany)        

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Have a look at the 4th picture

CLICK HERE TO GO TO mrboilwash's LINK on eBay

Post# 1037244 , Reply# 32   7/5/2019 at 16:57 by chetlaham (United States)        

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Oh man, I owe you big time! :)

Now that, is how you wire a stove. Very ingenious.

Do you know what the elements say left to right btw?

Post# 1037245 , Reply# 33   7/5/2019 at 17:11 by mrboilwash (Munich,Germany)        

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The ones on the left are the top oven elements (Bratrohr oben), on the right are the bottom ones.

Post# 1037262 , Reply# 34   7/5/2019 at 19:51 by chetlaham (United States)        

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Very elegant way of doing it.

So I would imagine one set of top and bottom elements for medium, both sets for high and in series for low?

Post# 1037267 , Reply# 35   7/5/2019 at 22:04 by combo52 (Beltsville,Md)        
Building an oven without a thermostat

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Is just plain stupid, If it was designed so it could never go over 500-600F it would be nearly useless for baking or broiling.


It would not get hot enough to broil well.


It would take too long to preheat for baking.


It would end up using more energy because it would take so long to preheat and then eventually overheat.


It would bake very poorly because it could not recover when food was added and would result in too much temperature fluctuation, a decent souffle would be impossible.


It would be dangerous as many foods would eventually catch fire, and wasteful as much more food would be ruined.



Yes at one time both gas and electric ovens were built without thermostats because thermostats were expensive or not available at a reasonable cost, these ovens were more powerful and could easily reach temperatures over 700 F quickly.

Many of these early ovens were destroyed by forgetful users, or the fire department when they responded to a fire, LOL


John L.

Post# 1037270 , Reply# 36   7/5/2019 at 22:51 by Tomturbomatic (Beltsville, MD)        

Underwriters Laboratories would never allow such a thing to be built and sold with their approval and without the UL sticker, they cannot meet requirements for sale because sellers have to be responsible for selling safe appliances just as manufacturers have to be responsible for not building and marketing dangerous appliances. Fire insurance companies would not insure a building with one in it. The concept is a fever dream of one who knows little of reality.

Knapp Monarch, Toastmaster and other brands made their cheapest models of table toasters without thermostats, but they were minimally powered units used with supervision. If you are interested in studying about these devices, the magazines are available.

Post# 1037271 , Reply# 37   7/5/2019 at 22:53 by chetlaham (United States)        
Food catching fire

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Not if you turn down the heat. Set to preheat- then turn it down a few notches. Even if left on preheat mode the elements would not be strong enough to push it past 550*F.

Preheating will take time though I can not deny this, and yes food will lower the temp taking time to recover.

But if played right I can see it working reasonably well.

Perhaps it might be time for me to look into PTC technology.

Post# 1037272 , Reply# 38   7/5/2019 at 22:57 by chetlaham (United States)        
UL listing

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What UL listing requires ovens to have a thermostat or a high limit?

"One who knows little of reality."

You have no way of knowing what I know and don't know, so saying this is just both dumb and silly.

Post# 1037313 , Reply# 39   7/6/2019 at 13:34 by chetlaham (United States)        

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Can you hook me up with the magazines or listings for Knapp Monarch and Toastmaster?

Post# 1037394 , Reply# 40   7/7/2019 at 06:24 by retro-man (nashua,nh)        

Just to throw this out here, I was thinking about this thread and came up with an idea. Would not it be just easier to take a more "modern" stove and remove the temp control and add in 2 burner controls, one for the bottom element and one for the top element. You could control the amount of heat being put out by both with the burner controls and adjust as needed. Just a thought.


Post# 1037415 , Reply# 41   7/7/2019 at 12:58 by chetlaham (United States)        

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Its a good idea, thank you! I intend to try a variac to get the exact wattage that will stabilize a temperature, but before that I would need to improvise so your idea and combos idea would work out well. Wiring the bake and broil element in series would work to in giving me a lower wattage and going from there.

The helpful folks aside... considering that Tomturbomatic is now at 2 likes maybe its better that I don't share these ideas with the world. People come here to escape the judgment offered by the public, only to receive it by a certain group of inviduals on here.

Post# 1037417 , Reply# 42   7/7/2019 at 13:29 by LowEfficiency (Iowa)        

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>> maybe its better that I don't share these ideas with the world

Don't take it that personally, it's more just that you're requesting information/assistance toward making a product "worse", which is a difficult ask for others to provide helpful advice toward. It might make sense to you, but to most other folks, it's just hard to understand why you would want to do this project at all.

Post# 1037419 , Reply# 43   7/7/2019 at 14:06 by chetlaham (United States)        

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People are free to think its a bad idea warranted or not as much as they want, but can reserve typing out personal attacks. Yes it says more about them then it does about me, but for a place where its supposed to be safe to share these ideas it becomes rather disheartening. Yet ironically I would think (expect) thats why those people are here- to be safe from judgment.

Sure in some ways a thermostat free oven is a down grade in performance, but in other ways its a plus, good enough that PRC is doing it today. Then there is also the fact I want to see why this is a bad idea for myself. A lot is learned in the process like thermodynamics, series/parallel circuits, math, ect. "Violating" the "norm" should be seen as a good thing.

Post# 1037426 , Reply# 44   7/7/2019 at 16:30 by Stan (Napa CA)        
Hi Chetlaham

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This won't answer your questions, but does show a example of a gas stove (currently in use) that has no thermostat.
(Original question)
The oven has one valve to open to control flame.
The # of jets for oven flame probably equal to two stove top burner jets together. I never open this valve all the way because I fear flame is too much to fast. During preheating, and If not babysitting, oven temp can easily reach 600 degrees in 15 min.
I'm so use to this stove.. I really don't think about it much because I just kinda know what flame height gives me 350 degrees. I also hang a oven themometer for accuracy.
Since the broiler is directly under the oven flame, time and temp is regulated by raising or lowing what ever one is broiling to that flame..instead of raising or lowering oven flame.
It's all very low tech, but would be considered unsafe by today's standards..(As it probably should be) but works just fine me!

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Post# 1037434 , Reply# 45   7/7/2019 at 18:14 by chetlaham (United States)        
Much Appreciated :)

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Thank you- I am very interested in such ovens. Keep this as long as you can, you are lucky to have it. Comes in handy during power outages too.

Post# 1039654 , Reply# 46   7/28/2019 at 05:56 by chetlaham (United States)        

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Found one! :) <3

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Post# 1039655 , Reply# 47   7/28/2019 at 06:21 by retro-man (nashua,nh)        

Happy for you to find what you were looking for. Sort of what I had described to you earlier, but it's all complete and done. Let us know how this works out for you.


Post# 1039657 , Reply# 48   7/28/2019 at 06:28 by chetlaham (United States)        

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Well at least web page of one. But I wish to try this on a modern GE/Whirlpool/Frigidaire oven. I have a feeling convection will make work.

I see a thermostat on these to the left- does it actually control anything? Is there an instruction sheet to this oven?

And is 120 applied any time to the elements?

Post# 1039673 , Reply# 49   7/28/2019 at 09:47 by Tomturbomatic (Beltsville, MD)        
RE: Reply #46

No, you did not find an oven without a thermostat. The chrome object on the left side of the oven is the thermal control. It turns the heaters on and off to maintain a set temperature. The switches vary the intensity and balance of the heat for various cooking operations. Roasting meats, for example, called for top heat set at medium to give browning of certain meats, while a large turkey roasted over several hours might only require low top heat or no top heat to protect the delicate breast meat while baking called for low top heat to produce delicately browned baked goods like cakes and biscuits.

If you want to see an oven without a thermostat, go to thread 80017 in the Imperial Section, offering Launderall Model LS1 machines, Post 1039449, photo 4 of 7. Behind the washer is a Westinghouse oven with a thermometer mounted on the oven door. You can easily find this by typing Launderall into the search box at the top right of the Imperial Section and choosing the thread.

Post# 1039684 , Reply# 50   7/28/2019 at 11:35 by chetlaham (United States)        

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Found it:

Looks like the Hotpoint.

Similar setup of varying the heating elements?

Post# 1039687 , Reply# 51   7/28/2019 at 11:54 by Tomturbomatic (Beltsville, MD)        

No, because this Westinghouse does not have a thermostat to cycle the current.

Post# 1039689 , Reply# 52   7/28/2019 at 12:03 by chetlaham (United States)        

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But that doesn't stop you from doing low/med/high if you wanted to.

Post# 1039698 , Reply# 53   7/28/2019 at 13:09 by Tomturbomatic (Beltsville, MD)        

The current flows through the thermostat which regulates the temperature regardless of the heat intensity settings.

Post# 1039700 , Reply# 54   7/28/2019 at 13:38 by chetlaham (United States)        

chetlaham's profile picture
"Westinghouse does not have a thermostat to cycle the current"

Which would indicate multiple wattage settings I think. Ie something like 1,200 watts to preheat, 675 watts to hold a steady bake temperature.

Post# 1039712 , Reply# 55   7/28/2019 at 15:58 by Tomturbomatic (Beltsville, MD)        

Perhaps, although your wattage ratings are very low for a 240 volt oven. Why not preheat on 3000 watts at 240 volts and then drop the voltage to 750 by dropping the voltage to 115? That early 1920s range with just a thermometer in the door for MONITORING THE TEMPERTURE was upgraded by the later 20s to various thermostatic controls for the oven so as soon as there was technology for AUTOMATICALLY CONTROLING THE TEMPERATURE of the oven, the non-thermostatically controlled ovens were a thing of the past.

Without the literature for the range with the non-thermostatically controlled oven, I cannot say how the oven heat was controlled.

Post# 1039719 , Reply# 56   7/28/2019 at 16:52 by chetlaham (United States)        
Preheating at 3000 watts

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Is doable, however if left in pre-heat mode the oven could over heat going above 600*F. Opening the door could result in user injury. Which is why the door is locked during self clean. With a lower wattage the oven can't over heat.

Post# 1039722 , Reply# 57   7/28/2019 at 17:15 by Tomturbomatic (Beltsville, MD)        

All you need to do is put a timer on the preheat operation or is that too technologically advanced?

Post# 1039726 , Reply# 58   7/28/2019 at 17:31 by chetlaham (United States)        

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Doable, but timers can fail. User can always keep re-setting it to preheat.

Post# 1039741 , Reply# 59   7/28/2019 at 19:05 by chetlaham (United States)        

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Just entering some numbers for future reference:

(@ 240 volts, stabilized steady state)

350 watts= 164.57 ohms

650 watts= 88.6 ohms

1000 watts= 57.6

310.77 ohms all 3 in series = 185.346 watts


1) 185 watts

2) 350 watts

3) 650 watts

4) 1,350 watts

5) 1,650 watts

6) 2000 watts

7th position could be added for 1000 watts only- not sure why it was never added.

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Post# 1039743 , Reply# 60   7/28/2019 at 19:13 by chetlaham (United States)        

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To add, in a 400, 600 1000 watt scenario I could see why 6 positions would suffice as 400 + 600 = 1000 /// so it would be redundant.

This of course if for the stove top burners.

Hard part for me will be calculating the heat loss (for the oven) such that X watts will maintain 375-400 degrees steady state.

If I apply the same concept, I could achieve 350, 400 and 450 degrees.


Cookies in my experience cook better at 375 then 350

I'd argue when temperatures are steady the actual temperature is of less importance.

My Breville smart oven has taught me that.

Lets not kid ourselves a typical oven, even a GE "true temp" fluctuates some 50* if not more.

On/Off is crude even when done with relays...

Post# 1039746 , Reply# 61   7/28/2019 at 19:22 by chetlaham (United States)        

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Post# 1039750 , Reply# 62   7/28/2019 at 19:39 by chetlaham (United States)        

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And my bad- 350+650 is also equal to 1000 lol.

Still confused why no 1000 watt setting.

Anyway, a modern US burner with two elements. Two elements are common in flatops for giving you a cookware size options, but what is odd here is that these two elements appear to both scale the full unit.

This is typical, where on element runs the center another the perimeter:

Another example of a dual wattage burner:

Post# 1039753 , Reply# 63   7/28/2019 at 19:48 by combo52 (Beltsville,Md)        

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I have never seen a household oven that varies 50 F as it cycles on and off unless it had a bad thermostat etc.


It is Impossible to build a decent oven that does not have a thermostat, in order for it to work properly it needs to reach temperature quickly, work in different temperature rooms from 50F-120 F and recover quickly from unpredictable oven door openings and vastly different temperatures of food being added from frozen [ 0 F ] to boiling or more, if you are out to reinvent the wheel an oven without a thermostat is not going to be the invention that wins you any recognition, LOL.


John L.

Post# 1039764 , Reply# 64   7/28/2019 at 21:02 by chetlaham (United States)        

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But it can win you $$$$$. Everything around you exists because people were capable of thinking outside the box, adding to what existed prior. We may not know the names of the engineers at Whirlpool or their patents but they sure are enjoying handsome pay. So yes, it won't win anyone recognition even if successful to the point of mass production.

In your experience, by how much do ovens vary as they cycle?

Post# 1039766 , Reply# 65   7/28/2019 at 21:07 by combo52 (Beltsville,Md)        
Cycling Range Of An Oven Thermostat

combo52's profile picture

Probably between 5 and 20 degrees F.


John L.

Post# 1039769 , Reply# 66   7/28/2019 at 21:12 by chetlaham (United States)        

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I can believe that. But also keep in mind you have hot and cold spots along with uneven temperature distribution. Breville went to great lengths to eliminate that too and the difference is night and day.

An oven with more even, steady temps can make up for overall high or low temps.

Post# 1039771 , Reply# 67   7/28/2019 at 21:14 by chetlaham (United States)        

chetlaham's profile picture
And oh, John, before I forget- why the double elements? What was Whirlpools reasoning behind this?

Post# 1039776 , Reply# 68   7/28/2019 at 22:11 by LowEfficiency (Iowa)        

lowefficiency's profile picture
>> why the double elements? What was Whirlpools reasoning behind this?

That's probably one of the "rapid boil" or "turbo boil" elements.
They let you put a LOT of heat, or a smaller amount of heat, into the same size cookware... with much more stable temperature regulation when using lower heat settings.

Post# 1039793 , Reply# 69   7/29/2019 at 06:23 by Tomturbomatic (Beltsville, MD)        

The engineers working for a corporation do not get paid for their patents; the corporation claims the patents in the name of the corporation.  Your thinking is not outside of the box.

Post# 1039799 , Reply# 70   7/29/2019 at 07:00 by chetlaham (United States)        

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Yes- but my point was having your name on a patent is an accomplishment even though most people could not put an individual name to a patent.

Considering how much stoves vary in temperature and how uneven they are, it is indeed out of the box thinking how to correct it.

Breville smart ovens cook better then most 2,000 dollar ranges.

Post# 1039800 , Reply# 71   7/29/2019 at 07:01 by chetlaham (United States)        
Rapid boil

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Does anyone have a link or service manual bulletin that describes it?

Post# 1039805 , Reply# 72   7/29/2019 at 07:10 by combo52 (Beltsville,Md)        
Reply #66

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Note the thermostat built into the element to protect against overheating the glass Cook-Top, the reason for the dual elements is described in the service information for this range.


John L.

Post# 1039807 , Reply# 73   7/29/2019 at 07:28 by chetlaham (United States)        

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Thanks- which sheet / page?

Looks like Low Efficiency is correct- it is a rapid boil feature.

Post# 1039808 , Reply# 74   7/29/2019 at 07:30 by chetlaham (United States)        

chetlaham's profile picture
And oh- won't the 1,100 watt element over heat the cooktop because its not run through the thermostat?

Post# 1039812 , Reply# 75   7/29/2019 at 07:56 by henene4 (Germany)        

Why not an variable voltage solution? Or high power PWM solution?

Most safety systems could be run on timed modes as well, and no relays to fuse shut.

Would still include a one shot thermostat for fires though.

The shorter the operating times will be the more exact it will, the longer the more you draft off.

Post# 1039900 , Reply# 76   7/29/2019 at 19:27 by chetlaham (United States)        

chetlaham's profile picture
Simpler- but come mass production those things would probably have to be taken seriously.

Post# 1039916 , Reply# 77   7/29/2019 at 21:55 by earthling177 (Boston, MA)        

I find it weirdly ironic that you keep mentioning the Breville smart ovens.

Yes, they *do* work very well, that's true.

And they do have multiple elements.

But they are very possibly the or one of the most over controlled ovens -- the microprocessor even sports anywhere from 6 to 13 (possibly more by now) different programs to deal with cookies, pizza, regular baking, roasting, toasting, some have slow cooking, or air frying features etc.

The entire thing is basically a demonstration of what a few highly sensitive low inertia sensors plus a microprocessor can do with 5 to 6 elements.

It's possibly the furthest thing one could have from a handful of elements coupled to a switch that puts the elements in series or parallel to achieve different power levels, each element on the Breville is connected to circuits that vary the power very closely according to the program and temperature sensors, and, if you look at the elements during a cycle, even for toast, for example, you'll see them cycling from off to several different power levels to achieve multiple different functions, like raise the temperature of the toast, dry it, then they turn on the central broil element to toast the surface etc.

Post# 1039968 , Reply# 78   7/30/2019 at 08:03 by chetlaham (United States)        

chetlaham's profile picture
100% true- however- the temperature is inside is steady and very even.

My theory is that if you do not open the door to a none thermostat oven, the temps inside will remain rather stable and not bob up and down.

Post# 1039994 , Reply# 79   7/30/2019 at 10:06 by combo52 (Beltsville,Md)        
reply # 78

combo52's profile picture
No it does not work that way, if you do not open the door it will keep getting hotter

You have no concept of how things work, I can see why you are hiding from the world, LOL

Post# 1039999 , Reply# 80   7/30/2019 at 10:35 by chetlaham (United States)        
Keep getting hotter

chetlaham's profile picture
Sorry but this really is tit for tat. You don't understand thermodynamics even in the most fundamental sense. Which is why someone with a more advanced understanding would appear dumb to you. Because its going over your head.

At any given wattage you will eventually reach an equilibrium.

The temperature will rise such that heat loss will equal element's heat input.

It is physically impossible for a 250 watt element to bring a typical stove to 600*F. But it will get warm inside for sure.

Post# 1040019 , Reply# 81   7/30/2019 at 13:55 by LowEfficiency (Iowa)        

lowefficiency's profile picture
>> My theory is that if you do not open the door to a none thermostat oven, the temps inside
>> will remain rather stable and not bob up and down.
>> ...
>> At any given wattage you will eventually reach an equilibrium.

Again, Yes, it could be done, and Yes, you could bake things in an oven made this way.

But you're still missing the big picture. That equilibrium equation includes losses due to opening the door (necessary to put food inside to cook, or to check cooking progress), the thermal mass of the cold food and cookware you put in, the temperature, humidity, drafts, etc of the external environment in your kitchen, the materials and insulation of your oven, the insulating value and thermal mass of surrounding floor and cabinetry, whether your nearby refrigerator is running, whether the lights are on, whether the sun is shining through the window, what season it is, whether the oven light is on, etc.

It is very easy to design a simple temperature-regulated control circuit to hold an oven at a specified temperature +/- a tolerance, regardless of the outside conditions. It is near impossible outside of a carefully controlled lab environment to reach that same temperature at an equivalent level of temperature stability by equilibrium alone.

So what do you do?
If you set the heater wattage to reach that theoretical equilibrium point at a sane cooking temperature, you have to deal with an oven that for practical purposes never reaches temp. Because with cold food put in, the time it takes to recover is on par with the total time you cook for.

If you set the heater wattage to be higher to account for that, to bring the temp up faster and keep cook times in check, then your equilibrium point is a much higher temperature and leaving it on will burn your food if left alone.

If you increase the thermal mass of the cooking appliance to improve temp stability (cast iron stove walls, etc), you increase the warm-up time considerably, worsening the problems above. If you reduce the thermal mass of the cooking appliance to improve warm-up-to-equilibrium time, you worsen the impacts of opening the door or inserting food.

See the problems?

Post# 1040021 , Reply# 82   7/30/2019 at 14:02 by chetlaham (United States)        

chetlaham's profile picture
I like your reply. All true.

Post# 1040102 , Reply# 83   7/31/2019 at 06:19 by retro-man (nashua,nh)        

Just to throw this in the mix, how about the old wood stoves with the oven built in. The fire was going constantly to keep heat going, but you could adjust the fire to hold a pretty constant temperature. We had one in the basement at my parents house and if it was on my mother would bake down there all the time and the results were outstanding whether it was cakes cookies chicken or roasts.


Post# 1040157 , Reply# 84   7/31/2019 at 13:22 by kb0nes (Burnsville, MN)        

kb0nes's profile picture
I think they should build passenger cars that only have enough horsepower to only drive 65 mph...

Same idea. And it would work equally well.

I may have missed a comment as to why in the hell would this idea have any merit, I scrolled by half of the thread.

I LOVE any system that has feedback control that allows it to be adaptive to work better. This is what a thermostat system is, closed loop feedback control. This is the reason why computer controlled appliances are adaptive and superior to old crude mechanical controls too.

Post# 1040212 , Reply# 85   7/31/2019 at 19:32 by chetlaham (United States)        

chetlaham's profile picture
I want to try it myself. Doubt it would ever hit mass production for obvious reasons, but the simplicity is kind of seducing for me. Its a good way to learn thermodynamics in person.

LowEfficeny- your post was very helpful to me. You touched on several issues I need to consider like thermal inertia trade offs.

At least the cooktop idea would work.

If you guys were to try this- what wattages would you choose for preheating and baking? Say you had an off the shelf Whirlpool or GE oven and could pick any wattage.

Post# 1040273 , Reply# 86   8/1/2019 at 10:22 by chetlaham (United States)        

chetlaham's profile picture
Well some good news to make folks happy... I am less enthusiastic about trying this now. Multiple door openings will lower the temperature to much, and to avoid it getting to low a temp a higher wattage element would be needed which would result in significant over shoot during long bake periods.

But the idea is still giving me a thrill.

Basically I was imagining a GE range with a knob like this:

With something like "preheat" "roast" "bake" "warm"


"preheat" "bake hi" bake med" "bake low"

Loved the feeling of the oven selector knob turning when I had the GE range years ago. It was several steps up from this:

Post# 1040369 , Reply# 87   8/2/2019 at 05:11 by mit634 (Sydney)        

mit634's profile picture
Hi All,

Here is an Australian General Electric (AGE) Hotpoint stove I own that has no thermostat control for the oven; only a thermometer built into the oven door.

The upper and lower elements each comprise two banks of nichrome wire coils in ceramic holders. Each element has a 3-heat switch that switches the two banks in series (Low), one bank on full heat (Med.) and both banks in parallel on full heat (High).

It is the same model of stove my grandmother used from when her house was built in 1948 up until the late 1990s. She used to bake, broil and roast in it daily. To preheat it she would put both elements on High. Once the thermometer showed approximately the right temperature, she would switch the top element to Low, and leave the bottom element on High or switch it to Med. She never needed to adjust the switches again while cooking to regulate the temperature.

The oven interior is very small, has a very thick layer of asbestos insulation around it, and the outer shell is thick cast iron. I believe all of that combined makes the heat regulation very stable despite having no thermostat.

Regards, Tim

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Post# 1040373 , Reply# 88   8/2/2019 at 06:30 by Launderess (Quiet Please, There´s a Lady on Stage)        

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Post# 1040408 , Reply# 89   8/2/2019 at 15:02 by chetlaham (United States)        

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Thank you to both! These posts are immensely inspirational. Its comforting to know that oven was able to bake and broil without major performance issues.

By any change, do you know the wattage of each element in the Australian Hotpoint?

Post# 1040409 , Reply# 90   8/2/2019 at 15:03 by chetlaham (United States)        

chetlaham's profile picture
And oh- if both top and bottom heat are set to high- will the oven go past 600*F is left to run indefinitely?

Post# 1040426 , Reply# 91   8/2/2019 at 18:21 by chetlaham (United States)        

chetlaham's profile picture
BTW, take a look at "our story"

It has a picture of one of those stoves:

Post# 1040832 , Reply# 92   8/6/2019 at 04:13 by mit634 (Sydney)        

mit634's profile picture
Hi chetlaham,

The top and bottom elements of my AGE Hotpoint are 1300 watts each.

I tested today how hot it would get if both elements were left on High.

It got so hot that the thermometer went off the end of its scale (550F), at which point I turned it off, and so it appears it would easily get to 600F if left switched on High.

Interestingly 5 hours later it is still warm and so the large thermal mass and good insulation appear to be the key to its ability to maintain a stable cooking temperature without a thermostat. I guess old solid fuel stoves used a similar principle.

Thanks for the link to the Hotpoint website !


Post# 1040843 , Reply# 93   8/6/2019 at 06:26 by combo52 (Beltsville,Md)        
Old AEG Hotpoint Electric Oven

combo52's profile picture

Hi Tim, At a total of 2600 Watts your oven left on will easily Self-Clean itself and go over 1000 F as well, I would not recommend it though on something that old as it could buckle some metal parts or ruin some wiring etc.


I used to hear stories of purple burning off soil in old electric ovenlike yours, even the owners Manuel suggested burning the top elements clean [ the open coil ceramic type ] by placing a metal pie pan oven them and turning them on high for 15 minutes.


Thermostats are wonderful things to have on a range, NO MANUFACTURER would ever build an oven with a heat control system and thankfully we are starting to get maximum heat limits on surface elements as well, they are even working on gas surface burners as well to make them safer. 


John L.

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