What is the issue with having a water softener?  Two years ago we replaced a 20 year old water heater.  The insurance company installed one that says a Rheem Professional.  In this house the water is softened before the water heater.

The water heater (30 gal) in this house is about 40 years old. I replaced the anode rod about five years ago. It was about 50% gone.

The water here is naturally reasonably soft (sierra mountain water) so no softener is needed.

The heater does tend to bump and grind while heating, which I assume is from debris at the bottom of the tank. But, no leaks. I drained it about five years ago, some debris. I guess they don't make them like that any more.

I have a spare 20 gallon heater just in case. A neighbor was selling his house and the realtor made him replace the water heater he'd installed about 7 years earlier. I've never hooked it up but I figure it would be fine in an emergency. I might scout around for a replacement 30 gallon before the California ban on gas powered heaters takes effect.

Well, as far as anode rods go, if you're handy and have a very big wrench, it shouldn't be too difficult to pull the anode rod yourself. I recommend getting a spare in advance just in case.

If more than 50% of the original is gone, I'd recommend replacing it.

Make sure the water heater is braced well before wrenching on it. The last thing you want is for the water and gas connections to be damaged.

Greg, you ever thought about a Gas tank-less? That's what Dad  put in at the farm and its wonderful.Water heaters don't last at the farm because, the well water has sooo much mineral content  in it.Its very clean water but, very different water almost tastes carbonated.

My Dad got a Rinnai , I don't know much about them save for knowing I want one but I don't have gas at my place.  I am getting a Tank-less electric when mine goes. There is only one size electric tank that fits in my place a Bosch 38 gallon  and there $$$$ as hell.

We have a Maytag water heater, made by State Industries. It's easily 15 years old. 

When we first installed it, we had to change the anode rod, because of a reaction it was having with our water, had a bad smell. Been trouble free since.

We have lived here since the house was built in 1968 and we are on our 5th water heater.  4 of the 5 have been Ruud.  One of the Ruud lasted 18 years.  We had one Bradford-white and it lasted 8 years.  We did have expansion tank installed about 10 years ago.  We have gas hot water and our current is a 40 gallon Ruud installed in 2016 🫣

We replaced the ancient electric water heater in our home in July of 1998 with a 40-gallon Ruud natural gas heater w/ a Power Vent. We bought the house in June of 1998. It has given flawless performance ever since. 

The reason the electric water heater was replaced so soon was that it couldn't keep up with doing two loads of laundry back-to-back. The only time the gas heater has run out of hot water was my fault when I decided to wash a load of laundry, run the dishwasher, and take a shower all at the same time.

I found this little article tonight to be both informative and helpful.

Here is an excerpt, and the full link is below:

Is a Popping Water Heater Dangerous?

How to flush the water heater tank

To prevent popping sounds and damage to the water heater and the surrounding areas, flush your tank. The process is elaborate, but after a few times, you should be a master. If there is ever a safety concern or if you do not have the DIY mindset, contact a professional plumber to inspect and flush out the tank. 

1. Turn off an electric water heater at the circuit breaker. For a gas heater, switch the gas setting to "pilot."

2. To stop extra water from getting into the water heater, adjust the lever to the cold water to a 90-degree angle. 

3. Affix your garden hose to the drain valve and place the opposite end outdoors or in a basement drain to extract the hot water.

4. To get the water pumping through the hose, open the pressure valve and turn on a hot water faucet elsewhere in your home. 

5. You can now open the water heater spigot or drain valve. Be cautious as the water will be HOT when running through the tap. 

6. Once the water has fully drained, the flushing process can begin. Close the pressure valve and then turn on the cold water lever. Switch the lever from open to closed several times to flush out leftover sediment. 

7. Once the water coming out is clear, this part of the flush is complete. 

8. Shut the water heater spigot or drain valve and detach the hose. 

9. Align the lever to the cold water with the water inlet pipe.

10. Let the water heater tank refill, which should take roughly 10 minutes. 

11. To release the air from the tank and the pipes, turn on a warm water faucet. Turn off the fixture when the running water is clear and no longer murky or cloudy. 

12. Return power to the water heater at the circuit breaker for an electric water heater or turn the gas line from "pilot" to "on." 

To eliminate the possibility of a water heater explosion or concerning sounds coming from the unit, regularly flush the water heater tank every six months. Consider installing a salt-free water conditioner in your home to improve your water heater's efficiency and prevent sediment buildup. 

The water heater here might be a bit of a concern. I may have mentioned already that I've got a spare, from a neighbor that was moving and put it out on the street because the realtor told him he couldn't sell the home with a WH that was near end of life.  It's a six year warranty, A 40 gal GE, but my understanding is that they are all basically the same, the warranty just covers a longer period but costs more.

In any case, I just went out an pulled the anode rod on the spare water heater. It's mostly intact, maybe slight wear on about 1/3 of its length. If and when I need to put this one into service, I have a couple of spare anode rods that should work just fine, so just in case I'll put one of those in. And yes, I'll flush the thing out. I got a narrow beam flashlight on the anode rod hole, and while there is some white (probably anode rod) stuff on the bottom it's minimal. So as long as it fires up and heats OK, should be good to go.

The attached link is a good source of info, and confirms my suspicions about water heater longevity, anode rods, etc. The water heater that come with this house 25 years ago is bumping a bit. I have wrapped it with a thermal blanket, so I can't easily view the details, but as I recall it's a Montgomery Ward brand. Who knows who made it? And it's probably a 40 gallon, not a 30 gallon. I'm planning on giving it a somewhat overdue drain session soon so we'll see if that helps with the noises.

I'm no fan of cold showers, but I've been washing my hands with cold water for the past few months. So far the water out of the cold tap isn't too cold, but as winter progresses that might change.