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.
Spares
Spares4Appliances is a spares company run by repair engineers who understand all about spare parts for appliances.
Hello Marcus: Your experiment seems to confirm that in many cases, the hot water fill makes very little difference to energy costs used. When you factor in the fact that when hot water was drawn into the washing machine it usually draws litres of hot water into the pipework which gets wasted it probably costs more to use hot water.
I would tend to agree, however I’d say a difference in the order of 10% is significant, particularly when taking into consideration that my hot water tariff is >>10% cheaper. I’d also suggest the difference (savings) would be greater on warm washes compared to hot, but the testing involved would take more time & energy than I’m prepared to spend ;).
Savings would increase on hotter washes but 10% of such a small amount is negligible to me. 0.4 cents saving per wash isn’t worth pursuing, especially when you take into account the wasted hot water in the pipeworks.
marcusbrutus, can you tell me how much energy, in kWh, that your machine consumes on average? The tiny gains that you are experiencing indicates that your machine (Fisher&Paykel WH80F60W1) just like LG does not use the hot intake very much. This is however a problem with these machines and not a inherit problem with hot fill machines. One conspiracy could even be that these manufacturers makes “poor” hot fill machines just to “demonstrate” that the concept as such is flawed…
I’ve done some measurements with a Kill-a-watt on my Rex Sunny now. It seems to work as advertised. For example, a synthetic 40 degree wash only consumed 0,45 kWh. I think this is great and not at all negligible.
It seems like there’s still room for improvement, however: The machine always fills using both the hot and cold intake at the same time, thus blends the hot water with cold. This problems gets worse at the winter, since the cold water is very cold, just a few degrees celsius. If the machine instead filled using only hot fill until the water was warm enough, by measuring the incoming water temperature, then the savings could be even larger.
I don’t know if you are referring to my comment about negligible Peter, I think anyone who thinks that 0.4 of a cent is a significant saving must be pretty hard up or pretty a Scrooge like :-)
On a 40 Deg wash, if the washing machine filled with hot water only at first as you suggest it could damage laundry as most people’s hot water is at least 60 Deg C. Hot water coming into contact with certain stains can also set them in and make them extremely difficult to remove. For that reason washing machines are never likely to fill with hot water only on a 40 Deg wash.
Peter,
I will hook up the power meter again and measure kWh/wash when it’s finished doing it’s current job.
My comment about 0.4 cents is by no means an average, and keep it mind it was on one of the warm cycles, as opposed to a hot one. I still view it as (in the order of) ~%10 percent. Considering what the machine actually does (spin+rotate+time, etc) I would regard this as significant, particularly as I would expect that the hot/cold mix during fill of that particular cycle means that the effect of the hot water is lower.
I’m now using “Allergy 40” as the most common cycle so I expect the percentage difference to be even lower … we’ll see.
“cent” is not a very good measurement, since the energy cost differs a lot. One example with the Rex is comparing a 60 degree cotton wash in standard versus hot fill plus quick mode (which is only available with hot fill). In this case, the energy consumption goes from 1.4 kWh down to 0.55 kWh, thus this saves 0.85 kWh. With Swedish energy prices, this corresponds to roughly 0.1 Euro. This is significant.
The idea is to use a temperature controlled fill; to measure the water temperature, and then activate the cold fill only when the incoming water is too hot. As pointed out on this page, the first litres are “cold” anyway.
I would say that it is extremely uncommon that the hot water is more than 60 degrees, at least here in Sweden. If it was, people would get burned every now and then. Besides, you wouldn’t be allowed to connect the Rex Sunny at all, since it requires that the hot water is 60 degrees or less. My new Bosch dishwasher has this same requirement.
Sure, whatever. I don’t really care, if that would happen, I’ll just throw away this piece of clothing and buy a new one. Fashion changes anyway. And you can always disable the hot fill if you really want to heat the water slowly; if you know you have a bad stain.
The concept of manufacturers conspiring to “prove” that hot water inlets are no good is certainly interesting. You’d think that they would not want to do this for fear of damage to their reputations, however I know that there is a Government Document available on the WWW which I read once a year or so ago in which the Government is proposing to “persuade” manufacturers top drop hot fill on the most scientifically dubious grounds I have ever seen.
One does start to wonder who is pulling what strings here ………
I’m with Peter (post 222) – on my LG “allergy” cycles use about 50% extra water on each rinse, do 4 rinses not the usual 3 and rinse for longer on each rinse, so overall water use is well and truly increased. The Allergy cycles also heat up the final rinse water to 30 degrees to release any remaining soap, so hot water fill is certainly very beneficial on this machine.
My mum’s Miele also has allergy options which also increase the water level of the rinses, so I’d guess that most manufacturers / machines with Allergy options are going to use more water and possibly more electricity to heat water than on “non-allergy” modes.
I asked Miele again about the availability of the W 3841 WPS Allwater in the UK.
This is what they said:
Thank you for your email. The Allwater concept is beneficial if the washing machine is connected to hot water, rain water or well water. Whilst the concept is fantastic and very eco-friendly, the market potential is almost non-existent in the UK. This is turn means that Miele UK will not introduce the Allwater machine in the foreseeable future. I apologise for any inconvenience caused and please do not hesitate to contact me should you have any further queries.
Kind regards,
L****
Customer Support Advisor
Miele
I have responded requesting further clarification as to what is considered to be a sufficiently large “market potential” given that Miele is, almost by definition, a quality / “niche” brand that is not in the business of beating the likes of Hoover et al to the top of the volume shipment league.