Cold Fill on Wahing Machines

[BJS]

Why do most washing machines now seem to have a COLD fill only. Being a wrinklie, all my previous machines have been hot and cold fill. By having a cold fill I can see a saving on gas but would have thought a big increase on electricity bills. Thanks for any advice.

[ChuckFickens]

Cold fill only heats the water that is needed for the wash.

hot fill generally means you have to heat a lot more water than the wash needs. you heat the water by gas, which then cools in the pipes so the machine then has to heat the water anyhow (as it's filling mainly with cold water from the pipes) that then leaves the pipes full of hot water that will just cool down again so the cycle repeats.

[buildersmate]

That's all very well CF, but, like the author of the question I've never been able to reconcile this with the fact that water heated by normal tariff electricity costs about 4x the cost in energy of gas.
I don't understand it either.
Being a cynic, I wondered if it has more to do with cutting the manufacturing cost or aligning with European housewives who seem to prefer cold-fill only machines.

[ChuckFickens]

the problem is that with the reduced amount of water that modern machines use they will be pretty much full of cold water by the time any hot comes through to the machine from a hot pipe, although it may be cheaper overall to heat water by gas with a washing machine you are heating the water twice, once by gas, and once again by electric after it's filled the machine.

If you can get rid of one of these heating stages it going to be cheaper, ideally you would have a couple of feet of well insulated pipes from the hot water tank to the WM so it gets hot water as soon as it starts filling, but this is not normally practical, so the easiest way to get rid of one of the heating stages is to just fill it with cold water.

The problem is no better with combi boilers as they generally take a couple of minutes for hot water to start running after a tap has been turned on and for this time you are burning gas for no benefit to the heat of the water going into the machine (and again all you end up doing is filling pipes with hot water so it can just cool down)

if you could time your washing machine with any other activity that will run off the cold water in the pipes (i.e. doiing your washing up) then hot fill would be better as the machine would get hot water pretty much straight away.

[RJUKL]

I had the perfect solution to this when I had a top loading (but automatic) Philips machine which I could fill from a hose on the adjacent Utility sink hot tap. This was because I always had a cylinder full of hot water which was heated by oil when the central heating was on. I could not see the point in allowing it to cold fill and then be heated by electricity when I had s cylinder already full of hot water.

However, last year I bought a new machine (top filled) only to find that its electronic programmes would not allow me to do this as it always automatically emptied any water already in the machine before it would begin a programme.

The reason most machines only have a cold fill is because the temperature of the hot water in nany houses varies and it could be too hot for some programmes. So in the past, with my machines, it was only in the 90 degree wash that the hot tap fill came into operation anyway. I also realised that the first gallon or so of this was cold anyway as the water had to travel so far from the cylinder to the machine which is how I came to fill it from the adjacent hot tap by hose, having run off the initial cold water first until it ran hot.

[RJUKL]

My perfect solution. I am on Economy Seven (installed in this house before I moved here) which means that the cost of overnight electricity is a fraction of the daytime rate. In my case the daytime rate is 16.018p for the first 210 kWh and then 8.938pfor the remainder. However, the night time off peak rate is a mere 1.86p for every kWh from midnight until 7.00 am (or 1.00 am until 8.00 am BST).
I use my machine on a time switch as I do the dishwasher and also all my hot water is heaterd off peak by a timer controlled immersion heater.
The difference in the daytime and overnight cost is ridiculous, so I use anything I can overnight.

[BJS]

Thanks CF for your reply it explains a lot to me. I live in a bungalow built in the late 50's with concrete fkoors under which the pipes run, so in this present cold spelll it exlains why it takes so long for the hot water taps to actually give hot water. Thans again for all the replies.