I’ve had several people ask if you can connect a cold fill washing machine to the hot water tap instead of the cold one. They were unhappy about the disappearance of the hot water valve in UK washing machines, and were wondering if they could circumvent the change.
Many people who are using solar powered energy to heat their water, or who had another cheaper environmentally friendly supply felt that the advantages of their environmentally friendly and economical hot water will be wasted by not using their hot water supply.
However, the answer to the question is no, for the following reasons..
Hot water supply is too hot
The incoming water temperature would be too hot (usually at least 60 degrees Centigrade). This can damage delicate laundry and shrink woollens.
There would be no way of controlling the temperature of the water going into the drum and onto the laundry.
A washing machine designed to use hot & cold water will control the temperature of the water in the drum by either filling with a mix of hot and cold – or filling only with cold water on all wash cycles except the really hot wash.
Too hot for most wash cycles
The temperature of household hot water is also too high for most commonly used wash cycles, which only need 30 or 40 degrees.
It is pointless putting on a wash cycle that needs to heat the water up to 30 or 40 degrees if the water is 60 degrees from the start.
So apart from potentially damaging some laundry, the washing machine’s thermostat would close almost immediately and the wash cycle would move on to the rinsing too soon. This would shorten, but compromise the wash quality.
Hot water not good for biological detergent
Biological detergent contains living enzymes. These enzymes are killed off at the temperature of most people’s hot water. So filling with hot water only would again compromise wash efficiency when using biological detergents.
Biological detergent is more effective when starting in cold water with the water gradually heating up.
Rinsing in hot water is very bad
If a washing machine is only connected to the hot water supply then obviously when it comes to rinsing the laundry – the water going in would also be hot.
So the laundry would be rinsed in hot water. This would cause severe creasing, as well as wasting all the hot water and being very energy expensive. Also hot water tends to activate detergent and create suds whereas cold water doesn’t and is therefore more likely to be better suited to rinsing laundry.
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What about connecting both hot and cold hoses to a cold fill washing machine?
You can’t swap the cold water supply for a hot supply for the reasons given in this article. However, there might be an argument for using a y-connector to connect both hot and water supply at the same time. However, this seems a lot of trouble for little benefit. You would need to manually adjust the water pressure of both supplies to get a balanced, “warm” combination.
But as hot water usually takes a while to run through the pipework, the chances are it wouldn’t use much if any on the wash cycle anyway. This is in fact one of the main arguments for cold fill only machines. It would do all the rinses in warm water, which may (or may not) be better. But it would also use a lot more energy.
A full explanation as to why almost every washing machine is cold fill these days is here – Pros and cons of hot and cold fill verses cold fill washing machines
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After reading all comments and a deliberating a little why could we not:
Install a well insulated tank of around 6-10 litres close to the washing machine which contains pressurised water heated to at most 45-50 deg from solarpanels. Connect this to the cold inlet on the machine via a mechanical thermo mixing valve set to 45-50 deg with cold water feed from house . When the washing machine or dishwasher is put into action on a standard 40deg wash it would empty the small tank of it’s warm water into the drum and be just about ready to start washing. Meanwhile the small tank has refilled with now considerably cooler water from the solar system so when the rinse cycles begin the machine would receive the cooler water.
Thoughts: This system may require some investment at first but surely would eventually benefit households or 4+ people. Pressure pumps and any electronics could be run from a battery charged by solar pv.
My Zanussi 25 yr old washing machine is not longer serviceable. All the components still work it’s just it make an alarming noise on a spin. I also suspect it’s not as economical as it could be.
I’m running a combi boiler which is about 2 meter from the washing machine, so hot water is delivered very quickly, consequently some of the arguments don’t apply to me regarding the benefits of cold fill.
Hot fills machines seem to be few and far between so have had to opt for a cold fill.
What I propose to do is to fit a switchable Y tap to the hot and cold supply. Work out the boiler setting to deliver say 35 c water.
I know it’s a little bit of faffing around, but what I’m planning on doing is:
Switch the Y tap to hot supply.
Set the boiler to deliver the correct temp water
Start the washing as normal.
Once the WM has finished with the hot cycle, switch the Y tap over to cold supply.
The main draw back to this is:
You’ll only get warmish water through the rest of the house, when it’s completing the hot fill. Only a problem is someone needs a shower.
You will need to be about to switch it over. (if you’re not, then just leave it with the cold fill)
The main drawback is human error. I’m liable to forget, so perhaps a kitchen timer will do the trick. As most people tend to only use a max of 3 programmed settings, the time taken (should) be easy to work out.
The other problem is trying the sell the merits of the process to the boss lady who does the lions share of the washing.
p.s I’d be interested to know the proportion of Uk households that have the old heating system with the tank in the loft. Everyone I know has a combi. I suspect it’s at least 50% have combi’s
One way you can make use of a reduntant hot water supply is by connecting it to the washing machine intake when doing a weekly cleaning cycle (ie no washing), The hot water is good for killing off mould build up.
I will make this clear to everyone who hasn’t read my comments in other blogs on the whitegoodshelp site: WARM WATER from start to finish is superior to cold. The key word here is WARM water and not hot.
If you can start off with warm water at 30 – 35C MAXIMUM, that is ideal and enzymes in biological detergents will not be affected, in fact the enzymes will work immediately. The problem with cold water is the enzymes won’t work until the water temperature is warm, so power is wasted warming the water from cold.
Yes, warm water to start with can cut down on the time performed washing, but modern washing machines wash for far too long, which is one reason (of many) why they are less reliable now and clothing looks worn-out quicker. Shorter wash times will only be a problem if the main wash time was too short, say if it was reduced to washing for just 15 minutes instead of 1 hour.
Again, as some readers will know by reading my other comments in different areas of whitegoodshelp – warm water rinsing is far better than cold – it dissolves the detergent and removes all perfumes – which have been found to irritate skin (watch out as virtually all fabric conditioners, except Surcare, have perfumes). Also the warm water rinses will continue cleaning the clothes, so you get extra ‘washes’ too. :) I can now use less fabric conditioner than I used to and the clothes feel softer now compared to when I rinsed them in cold water using more conditioner.
I’ve found it quicker to fill up a large jug from the hot tap and tip the hot water into the soap drawer – this is the only time the water must be hot, as the water that’s already in the washing machine is cold. It makes no sense having spare hot water going unused, as the shower uses the hot and cold taps and little hot water gets used elsewhere. It would be different if hot water was being used to run a bath, but most people have showers fitted, either electric showers or showers connected to the hot and cold.
I’ve got to say that after reading most of the information on this site that I still want a hot and cold fill washing machine as I feel that it would best suit our needs. One of the kids is sensitive to enzymes so we use non bio powder. I am eco minded and have solar panels being installed on my farmhouse which is undergoing renovation. I will have oodles of hot water from it and wood burning stoves. I have 4 very dirty kids and a dirty partner (stop giggling). We’re farmers and live on the farm hence there is an enormous amount of filthy washing to be done on a daily basis so we require a large capacity machine. Our house is being insulated to the nth degree, pipe runs are quite short and all pipes are lagged so although there will be heat loss it will be kept as low as we can manage. However our old water comes direct (no cold water tank) from our own spring and is very very cold. much colder than water that has been within the envelope of the house. So for us a hot & cold fill machine would be advantageous. I realise that my particular circumstances are not the norm but in more and more people are putting solar panels on their roofs and insulating their houses and apparently the incidence of asthma and exzema are increasing which may translate to more use of non-bio powder. So more people might be looking for a hot & cold fill washer. My remedy for my problem if I can’t find such a machine will be to fit a thermostatic mixing valve to the cold supply of the machine set at about 30 degrees. It might/might not work but hey nothing ventured nothing gained.
I have just bought a new cold water fill washing machine but there is only a tap connected to the hot water supply under the kitchen sink to connect it to. There is a cold water pipe but no tap and no where for the waste water to go what should i do and can i do this myself or roughly how much is it going to cost me to get it done? HELP!!
I think you may have to get someone in to do this. Was there a machine there before that was connected to the waste pipe. I think you can get a kit in B&Q to connect the cold feed to your pipe,but you will need to turn off the water and drill a hole in the pipe. This could be a disaster if you do it wrong. If you get someone in get a Price 1st there are a lot of crooks in the plumbing game as you probably know.
Depending on how far your sink is, you can get an attachment that fits onto the u bend of the sink waste pipe. A tap can be fitted by any semi competent DIY person as you can use compression fixing which have no need for soldering which requires a degree of skill and more specialist tools.
My central heating and water run off a Multi Fuel stove. I would have to be an idiot to pay for electricity to heat my washing water! I don’t think forty degrees washes clothes hygenicaly, this has been proven. It isn’t a problem to start with clothes needing a hot wash and end with clothes needing a warm wash as the hot water runs out. I don’t find the clothes any more creased if you shake them before hanging them out on the line. As for wasting water I use the water that is run off first for watering my tomato plants.
I’ve read through the debate on hot and cold fill machines but have a particular problem no one has so far mentioned. My cold water supply is very slow, the best delivery rate from our cold-only tap is 4.75 litres a minute. Combine it with hot tap and it goes up to 9.5 litres a minute. We have a very old hot and cold fill Bosch which is on its last legs but I can get no sense from any washing machine manufacturer as to whether their cold-fill only machines will work satisfactorily under these circumstances. They all say I need at least 1 bar of pressure (how do you test for pressure?) and somewhere in the region of 8 litres a minute. I have been warned off connecting the machine up to a the hot and cold supply via a ‘Y’ piece as it will upset the machines thermometer and will result in creased clothes. Any ideas anyone? Thanks in anticipation