What is hot fill?

Ebac are the only UK manufacturer of washing machines that let you use hot water already in your home to do your laundry.

Filling your washing machines with hot water - rather than cold - has many advantages. You may wonder that if that's the case - why have all the other manufacturer's removed hot fill features? The simple answer is production cost. Other manufacturers removed the hot fill components to reduce manufacturing costs - allowing them to lower prices. These cheap and cheerful machines are a false economy.

Even more expensive machines removed the hot fill features to reduce costs. Ebac hot fill machines allow you to do your laundry with water already heated in your home. This saves time as you don't need to wait on the machine to heat cold water in the machine. It saves electricity as your machine doesn't need to consume electricity to heat the water. It saves money as you are not using the expensive electricity to heat water that you already have heated available.

If you are a solar panel user - the savings are even greater. You effectively have free *hot* water to do your family washing.

Jeff Howell
Home and Building Expert

In recent years hot-fill washing machines have been hard to find. Or impossible, if it’s a British-built machine that you’d prefer.

Cold-fill washing machines have been the only ones available, which means that you have to use electricity to heat the water from cold – even if your home already has a tank of hot water sitting waiting in the airing cupboard, or a gas-fired combi boiler sitting in the same utility room as the machine.

Various bits of marketing-speak have been used to explain this. Such as saying that hot-fill washing machines are less reliable, because the rubber hose seals fail quicker. Or that hot-fill machines don’t really save money anyway, because most of the water entering has been sitting in a cold pipe run. None of this is correct.

Some salesmen have even told customers that cold-only washing machines are more “eco-friendly”, or even that there are UK or EU regulations banning the use of hot-fill machines. All nonsense.

There is no law or rule that requires new washing machines to be cold-fill only. Such machines are made purely to save on the manufacturers’ costs. They save by not having to fit a hot-water valve, a hot-fill hose, the wiring and electronics that tell the machine when to open the hot valve, and the internal hose leading from the hot valve to the soap dispenser.

These short cuts might save money for the manufacturers, but they are costing money to householders.

The fact is that heating water by electricity costs three to four times more than using gas or oil (depending on your tariffs). And if you don’t have oil or mains gas, and use Economy 7 (“off peak”) electricity to heat your hot-water cylinder overnight, there is still a three to four fold saving over using the much more expensive day-rate electricity.

Homes with solar hot water panels are even more disadvantaged, as their day-time hot water is effectively free (if you discount the installation costs), and it must be galling for those owners to have to pay for electricity to heat water in their washing machines.

Some industry sources try to argue that hot-fill washing machines do not really save money, because most machines are sited too far from the hot-water source. Their reasoning is that when the hot valve opens, the first water that flows in is cold, because it has been sitting in an exposed pipe run. And then, after the machine has filled, the hot water left in that pipe run will cool down, and therefore be “wasted”.

This argument doesn’t really stack up. Let’s take the case of a washing machine that uses 20 litres for the initial hot wash (the subsequent rinse cycles will all use cold water). If your washing machine is ten metres away from the hot-water cylinder, then the volume of standing water in the feed-pipe is only 1.3 litres for a 15mm copper pipe, or 2.8 litres for a 22mm pipe (the figures for plastic pipes are even lower, as they have smaller internal diameters). By far the greatest amount of water entering the machine will be pre-heated hot water from your cylinder. Even with a combi boiler (where a boiler-full of cold water might have to run off before the hot water flows through) there will still be a saving.

"As for the idea that, once the hot valve shuts off, the hot water in the feed pipe is "wasted", this discounts the fact that it will be warming the air in the house (in the winter) just like a radiator. Your room thermostat will detect this contribution, and shut the boiler down to accommodate it."