Hot water connection for the washing machine

Washing machines run in different programs - depending on the laundry you want to wash. There are also options for particularly economical, "normal" and intensive washing. All wash programs are also associated with a specific water temperature between 20 and 95 degrees Celsius. The water is brought to temperature by heating rods in the washing machine. "Electric" and "water heating" - many people immediately think of savings through a hot water connection for their washing machine. Afterwards we will tell you if this is really worthwhile.

Washing was always associated with a high energy requirement

Perhaps some of the esteemed readers will remember it or at least have seen it in a movie or museum: in the past, the laundry room was lit with wood in the laundry room. A lot of laundry had to be cooked at this time laboriously and exhausting. Then came the first full automatic washing machine. Even with these devices, washing with temperatures between 60 and 95 degrees was a matter of course.

Thanks to modern detergent efficient washing from 20 degrees

One of the main problems was detergents, which were able to fully develop their effect only at high temperatures. But times change. Above all, it is the different technologies, some of which can make dramatic progress. For washing, these are particularly efficient heating rods for heating the water, but also detergents that work very efficiently at wash temperatures between 20 and 30 degrees.

Also 30 degrees want to be heated first

Therefore, the trend is increasingly towards washing with a maximum of 30 degrees. But of course the water has to be heated to 30 degrees. After all, a washing machine needs more than half of its power only to heat the water to 30 degrees Celsius. If you wash at 60 degrees, the proportion of electricity used to heat the water is as much as 80 to 85 percent since the massive electricity price increases.

The savings potential of different washing programs

So you would think that the supply of already heated water, which is indeed present in the hot water tank of the heating system, would have to save enormous costs. Basically, this train of thought is also correct, as the Stiftung Warentest 2013 had clearly demonstrated:

  • 40 degrees coloreds, Miele W1747 WPS, 0.21 kWh with hot water connection instead of 0.67 kWh
  • 40 degrees color wash, Samsung WF 9844, 0.37 kWh with hot water connection instead of 0.91 kWh

Cost savings per year

The machine must always be fully loaded for the above values. This results in the following savings option per year:

  • Cost savings Miele at 580 kg of coloreds a year: 4.50 Euro instead of 14.30 Euro
  • Cost savings Samsung at the same amount of laundry: 5.90 euros instead of 14.50 euros

However, a hot water connection is usually not worthwhile

It would therefore be quite possible to save 10 euros on average electricity. Nevertheless, the economic efficiency must be questioned massively. There is simply in almost no houses a hot water connection. In addition, the hot water production in the house must also be designed very efficiently. This includes hot water from solar thermal or collectors, regenerative water pumps and the like.

The economy usually speaks against a hot water connection

In addition, at the latest from the 4th liter of water corresponding warm water must enter the washing machine. That in turn can be accomplished by a permanent circulation system. But: too much energy is needed here again for the project to remain economical. In addition, according to Stiftung Warentest, corresponding washing machines, which are suitable for a hot water connection at all, are to be expected significantly higher prices (from 650 euros).

Source: Stiftung Warentest Washing machines with hot water connection

Tips & Tricks

Nevertheless, you can save a lot of money with your washing machine. If you live in a region with very hard water, this also means a correspondingly high proportion of lime, which deposits everywhere where tap water is used. Here's how to descale your washing machine.

Under "Consumption of washing machines" or "Power consumption of the washing machine" we have put together valuable tips for you how you can save electricity and water with modern appliances, for example by professionally interpreting the European Union's energy-saving label.

Video Board: Front Load Washer Hot/Cold Inlet Hoses