I lived in Holland as an exchange student in 1973----38 years ago. The family who hosted me were somewhat above middle class. They lived in a semi-detached home with front yard and garden in back. The attic had been converted into two bedrooms for the youngest two of their five children, and each child had his or her own bedroom. Even I had my own room: a small office or storage room on the first (ground) floor had been converted to a guest room. For 1973, this wasn't a wealthy family but they lived better than perhaps typical middle class Holland of that era.

The house was built early or mid 1960s. There was no central hot water. Instead, there was a point of use, gas-fired water heater at each point where hot water was needed: kitchen and bathrooms (two bathrooms). The point is that an above-middle class family living in a home under ten years old had only point of use heaters, and that is how things were then. The laundry area was in the attached garage, not the kitchen, and there was no water heater at that location, so the machine (a top loading horizontal axis washer) had to have an internal heater. Had the machine been dual-fill, a point of use heater would have been required, thus raising the effective cost of the machine above the actual purchase price.

Central hot water is more common now in Holland than in the 1970s. I have a friend in a newly built townhouse and she has a gas fired storage tank (not tankless) heater on the top of her three floors, and central hot water at each point of use. Her 1960s townhome, which she sold to buy the new one, had point of use heaters at each required location.

Even in the homes of European friends with modern central tankless hot water systems, the laundry room is plumbed only with cold water, necessitating a cold water fill with integrated heater.

In the US, basic FL machines lack an onboard heater and cannot wash above hot water line temperature. I have a Frig 2140 with no heater, but it sits adjacent to the 40 gallon/160 litre gas storage tank heater, so hot water is not an issue unless two people are taking showers elsewhere in the house at the same time. The 2140 lacks even auto temp control, thought its next up the ladder sister model 2940 does have this feature. I rarely wash on hot, anyway, as warm takes care of most of my needs. Middle of the road and upscale models do have heaters, which activate only when wash temp above hot water line temperature is elected.  Heating is slow because of 120V current, and I've heard of "santise" cycles taking two hours or more,  due to heating time plus extended wash time.

Louis, quite possibly my host family's house might have had a similar system. All of my visits there (initially for three months; later visits while in university and thereafter) were May-September, when they weren't heating the house. I was never there during winter or late fall. If there was a central system, it must have been turned off during the warm months, since I distinctly recall having cold water initially come out of the hot water bathroom tap until the flame lit and then hot water miraculously appeared.

The other thing I remember was everyone having a MINIMUM of two middle names, and some with THREE middle names. Maris was often one of those names, even for boys. ;)  (e.g. Klaus Maria Brandauer, though he's Austrian; the same concept existed in Catholic areas of Germany and Netherlands). Although we lived in a "mixed"  area (neither Catholics nor Protestants predominated), there was a sort of de facto segregation, in that even nominally Catholic families sent their kids to Catholic schools, and Protestant families sent their kids to Protestant schools. The result was that I never met a Protestant during the entire summer. They weren't prejudiced, they were very liberal, it's just that in those days, there was only limited "mixing". See section IV below:

http://www.euresisnet.eu/Pages/ReligionAndState/NETHERLANDS.aspx

Sind einweichen und aufmotzen trennbar oder nicht trennbar?

Ach, richtige deutsche Grammatik ist nicht von Amis zu erwarten....