I still get people asking if I know of any washing machines with a hot water valve. This article gives a few suggestions – but you should read on first to fully understand the issue. It is not as simple as you might think. It could be a complete waste of your time looking for one.
Most washing machines now only have a cold water valve but many people instinctively don’t like this. We all know washing machines wash with hot water, so it seems crazy not to use the hot water we already have in our homes. Heating it all up from cold seems wasteful and unnecessary.
This apparent madness is even more annoying for people who have an environmentally friendly and economic source of hot water such as solar powered.
However, there is a good argument that because modern washing machines use so little water on wash – there is no need for a hot valve. It’s in fact more economical to use cold fill only on 40 ° washes for most (but not all) people as explained here – is a hot & cold fill washing machine more economical?.
What is the science behind cold fill only washing machines?
All this is explained fully in my article Should I buy a cold fill washing machine?
So are there any washing machines with a hot valve?
At the time of writing there are some LG & Statesman models with a hot valve. However, they don’t take in hot water at all unless you use a very hot wash cycle. There is alternatively a British made washing machine with a hot water valve. Ebac’s hot & cold fill washing machine is advertised as using, “Intelligent hot fill technology”.
Some Hotpoint washing machines appear to be hot and cold fill, but they are designed for cold fill because there’s only a cold fill hose supplied and a y-piece adaptor supplies both valves.
I suspect this is a temporary measure, and that subsequent models will just have the cold valve.
So hot and cold fill washing machines are currently very rare. But even if you find one, you need to know that the few I’ve seen rarely even use the hot water valve.
If most of your wash cycles are done at 40 degrees or less it will most likely never use the hot valve at all.
Related:
Several people have asked me if you can connect an environmentally friendly and economic hot supply to the cold valve to utilise it. The short answer is no, for more details read Don’t connect the hot water supply to the cold valve on cold fill washing machine
New comments on this topic have been closed. There were over 600 comments now trimmed down (below) to 233. There are very interesting discussions there.
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I’m interested in the posts around 137 onwards above, mentioning the cost of electricity and the potential savings with hot water fill.
My new LG with the A++ energy efficiency rating uses around 2.6 kWh of electricity to do a cottons 60 degree wash, even now I have it filling with 30 degree water from a customised domestic plumbing arrangement.
It uses pretty much bang on 1kWh for a 40 degrees cottons wash.
(incidentally, to me this suggests that the LG’s heater isn’t very efficient if it can raise incoming water at 30 degrees to 40 degrees for just a unit of power but needs almost 3 times as much power to raise the temperature by another 20 degrees……)
I’m in a 2 person household and generally do 1 of each of the above cycles per week. To me that sounds like around 50 x 2.6 kWh plus 50 x 1 kWh = 180 kWh per year. I may not be on the best Electricity Price deal ever, but my supplier currently charges 14.2p per unit (and slightly more for the first 800 per year) – so that’s a shade over £25 a year to run.
Now, Miele washers are, I believe, the “Rolls Royce” of washers and also pioneers of economy and ecology, so, how come (as far as I can see) Miele machines use more than an LG (based on post 135 by Washerhelp, above) but still get A++ energy ratings?
This is not, of course, so much a comment on the fill method (and indeed, if I was using cold tap water the cost of the washes would of course be higher and may bring the consumption more into line with that of a Miele), however LG claim that using the hot fill saves money and Miele claim that Hot Fill is no advantage (in the UK!!!).
So, my question is, how come A++ (for energy) can be awarded to machines that clearly use different amounts of power and are not equal in the efficiency stakes?
As Andy and I debated several months back, this casts a whole load of doubt over how much value there is in the A to G energy rating scheme. The more I look at it the more I distrust this scheme.
I’ll stick to a more basic way to measure efficiency: which machine has the longest life and uses the most efficient source of water possible?
Astrand: Thanks. This machine isn’t necessarily going to use the hot water any more than the LG hot & cold fill machine though. Utilising a cheap or free hot water supply needs a complete rethink and redesign by manufacturers. Any machine still with a hot valve is unlikely to utilise it except maybe on very hot washes which few people use any more.
Dave: If it uses 1kW to heat the water 10 degrees from 30 to 40 you could expect it to use another kW to get from 40 to 50 and then another to get from 50 to 60 so wouldn’t you expect it would use 3Kw? (at 1Kw per 10 degrees)
I would expect virtually all washing machine heating elements to be roughly the same. I’m not sure how efficiency would vary much between any washing machine’s heating element. I would expect them all to reach virtually the same temperatures if they have the same wattage rating. If one heating element is twice as powerful it would heat water in half the time but cost the same.
Likewise if one heating element was only half the wattage it would take twice as long to heat the water but as it uses half the electricity the cost should presumably be the same. In other words the cost of heating water to a set temperature shouldn’t vary that much, it’s more the time it would take that should vary, which is dependent on how powerful it was.
It’s the same principle as having a 2Kw electric fire and a cold room. Switching 1 bar on would use half the electricity that switching both on would, but it would also give out half the heat so take twice as long to heat the room.
I don’t claim these to be facts, it’s just how I assume it works.
Are you on the best tariff? I pay only 10.4p (for secondary units anyway)
The energy ratings are only given on 40 degree washes. Also bear in mind different drum sizes will produce different costs. A 7Kg drum washing machine will cost more to run than a 6kg or 5kg washer. The only way it’s more economical is if you wash more items and therefore reduce the amount of washes done in a larger drum capacity washer.
Thanks Andy.
You’re probably right about the 1kw Vs 2Kw argument and so on; and I’m not on the cheapest tariff, I know that. I am on Ecotricity’s “New Energy” tariff where they guarantee that 100% of their profits from my tariff are invested into building wind and wave generators, but it’s more expensive than their other tariffs which simply promise to match the price ofthe “leading supplier in your area”. (It’s about 0.6p per unit more than npower’s standard rate and they are the leading supplier in Sheffield.)
One thing I do wonder about on the heater business though is the position of the heater within the tub. My new LG’s heater is in a sort of valley or well moulded into the very bottom of the tub, so it’s heating vitually every drop of water (rather like in old Hoover single tub washers), but in the Hoover Electron 1100 I had the heater was part way up the side of the tub, barely below the water level. Since heat rises this surely means that, like an immersion heater in your hot water cylinder, the old Hoover heated only the water that the laundry actually sat in and not that in the sump but the new LG heats all in the sump as well as that in which the laundry sploshes about.
I suspect the real key to the economy business is, as Andy states clearly, that you need to have your washer running completely full to make it economical at all; and with a 7kg drum I will never ever have mine properly full unless I either keep my coloureds in the wash basket for about a month before I wash them or wash my towels about once every 10 days. Even the double bedding is only about 2/3 of a load in this washer.
Now, I really don’t want to set us all off at yet another tangent, but to me this suggests that all manufacturers a and all test institutions are really only interested in family sized machines, not small households.
Remember that 50% of not a lot is not impressive. The savings are only likely to be relevant if you do a lot of hot washes and don’t have a gravity fed hot water supply. Savings of 0.7 kWh is roughly about .05p to me at the moment. As we only do about one 60 degree wash a week, these 50% savings only amount to £2.60 a year.
Most people only wash at 40 degrees so the difference there is even less. A cottons wash at 40 degrees is quoted as using .77 KWh but with a hot & cold fill it’s quoted as 0.5 kWh. The savings there (assuming you actually get much hot water into the machine) are just 0.2 of a kWh, which if you paid 20 pence a unit would be 4 pence. So if you did 10 loads a week it would save 40 pence a week – £20.80 in a year.
£20 a year is still a saving, but what if the hot and cold fill washer is rubbish? Or not very reliable and breaks down several times? What if it isn’t as economical as better designed washing machines that are cold fill and A+ rated?
Also, what if every time the washing machine draws in hot water, all it draws in is cold water because all the water from last time that is left in the pipework and the fill hoses right up to the hot water tank is stone cold? Because modern washing machines hardly take any water in on wash by the time most people’s hot water actually gets to the washing machine the washer has taken enough water in and stops filling meaning most of the water drawn by the hot valve is not hot.
The result of this is that you have just drawn several litres of hot water into the pipework between the hot water tank and the washer of which the majority will just sit there and quickly cool down and be totally wasted. This would presumably cancel out the small quoted savings.
If you have a combination boiler the gas would have come on full belt to try and heat the water up but unless it’s right above or next to your washing machine you will still get the majority of water running through the hot water valve is cold or just luke warm. Just when the water starts to run nice and hot the washer has finished filling and shuts off leaving piping hot water in the pipework and fill hoses completely wasted and destined to go stone cold.
When figures are quoted comparing the energy used by a hot and cold fill over a cold fill they do not take into account any wasted hot water that gets drawn into the pipework. I’m sure if they did the savings would be wiped out.
I don’t believe the majority of people in the UK would be better off with a hot and cold fill washing machine and that any savings will be so small it’s pointless pursuing one. This is because current washing machine designs do not utilise hot water effectively since washing machines started to use such little water on wash and consumers switched to washing at 40 degrees and even 30 degrees. There’s even an advert now for detergent claiming to wash at 10 degrees and I suspect we’ll end up washing in cold water eventually.
I thought I’d already made this comment – but as I can’t spot it I’ll make it again.
It is true that the old technology of simply drawing hot and cold water simultaneously in the hope that the result will be about right will not work when modern machines use so little water. I don’t know the typical water consumption figures although I am sure they’ve been cited.
But if machines now use so little water, then one of the objections for having a pre-mix chamber, into which water could be drawn selectively so as to get the right temperature prior to its being pumped into the washing drum must no longer be valid. Although there isn’t a great deal of spare space in a washing machine there is some – and probably enough for a mixing chamber that needs only to hold a few pints.
The difference between A+ and A may only be several pounds a year, which is nothing to get excited about – especially if the A+ washing machine costs more to buy. I also don’t believe it takes into account the money wasted by cooling in the pipes which for many people will outweigh these savings as a hidden cost.
You can’t compare 50% savings on gasoline which could save someone many hundreds of pounds a year to 50% savings on washing machine energy used by A+ instead of A in a year which only works out at £2.60 a year. That was my point, “50% savings” is meaningless without context and the context of 50% savings on something only costing £5 means that the apparently impressive percentage amounts to a very unimpressive amount.
When I said, “what if the hot and cold fill washer is rubbish?” I was being more general than the phrasing implied. It was a point taken from my general advice about guarding against focussing so much on getting a washing machine with a hot valve that you take your eye off the ball and end up with an inferior washing machine in other ways that can cancel out any potential savings.
The rest of your comments I’m afraid I disagree with. Hot water pulled into plumbing pipework only to cool down is definitely wasted water. Saying it will heat the house is wishful thinking indeed :-) Also, it doesn’t matter if thousands of people would be better off with a hot valve while ever hundreds of thousands of people wouldn’t. Things are designed for the majority as that’s where the sales and economies of scale are. In many cases a few companies can carve a little niche for themselves by supplying products for the minority, but these products always cost much more because of the vastly reduced sales. The problem with the hot water issue is that cold fill washing machines currently can function using only £26 of electricity in an entire year, so most – if not all of the savings will be wiped out by the inevitable extra cost of designing a hot fill washing machine that truly utilised a customers hot water in a truly economical way.
Current washing machines do not utilise hot water effectively or efficiently including the Rex machine. They are still based on the times when washing machines drew in much more water for the main wash by which time some hot water had time to run in and actually make a difference. Now that washing machines hardly use any water on the main wash just energising a hot and cold valve simultaneously does not get much if any hot water into the machione before it’s finished filling for most people.
This has been discussed at length and proved beyond doubt by the figures you quoted from the Rex where a cold fill machine is quoted as using 0.77 KWh but with a hot & cold fill it’s quoted as 0.50 kWh. The savings there are just 0.2 of a kWh which is neglegable.
To utilise water effectively would need a total redesign. If water is available to you freely at around 60 degrees how come the Rex machine only saves 0.2kWh which is a pathetically small amount? It’s because it needs a completely different approach to drawing water in to use the hot water you have available than simply just switching the hot and cold valve on for a minute.
Richard: This “hot” topic is split over two separate articles so it may have been on the other article.
I agree it could probably be done. The water could then be used on the rinses so it wouldn’t be wasted. You would still have the issue though of hot water being drawn into the plumbing system and laying in the pipework between the boiler or tank and the washing machine. This hot water would definitely be wasted unless a second wash was initiated to use it before it cooled down but as soon as you stop washing there will be potentially several litres of hot water drawn into the pipework which is guaranteed to go cold.
It would probably only be of major benefit to those of us who get our hot water free – although most would probably save a certain amount providing their hot water isn’t derived from full-price electricity.
And as I mentioned in my last-but-one comment, if such a machine was designed to cater for the minority it would inevitably cost more and wipe out much or all of the potential savings anyway.
Point taken – if such a machine were only useable by those who had cheap hot water. But such a machine would not be useable only by those who wanted to use dual fill – it would be equally useable by those with cold fill only without any modification apart from blanking of one of the intakes.
So the one re-design would suit all classes of customer – a wonderful sales opportunity I’d have thought.