I get a lot of queries from people who’ve discovered modern washing machines are cold fill only but still want to use their hot water supply. Many are very frustrated because they may have a “free” hot water supply where maybe their hot water is included in their rent, or they have invested a lot of money in a solar powered or otherwise eco-friendly hot water supply and are furious that none of their domestic appliances use hot water any more.
You can’t just connect the cold fill washing machine to the hot water supply instead of the cold because of the reasons in this article – Don’t connect the hot water supply to the cold valve on a cold-fill washing machine. However, some people are thinking laterally and wondering if they could connect the hot and cold fill hoses to the washing machine using a y-connector so the washing machine would receive a blend of hot and cold water.
All I can say is that theoretically this could work, but without a thermostatic control valve it would be difficult to get the mix right so the washing machine only ever received “warm” water. If the washing machine received water which was too hot then the problems mentioned in my Don’t connect the hot water supply to the cold valve on a cold-fill washing machine article would come into play.
Also, cold fill washing machines are designed to perform better when using biological detergents or detergents designed for low temperature washes. They start from cold water and slowly heat it up, which manufacturers claim gives better wash results. If you supply the washing machine with water already heated it could affect wash results by not utilising biological detergents optimally or by potentially speeding up the wash time. This latter point sounds great, we are all frustrated with how long washing machines take to wash these days, but wash efficiency could be compromised if the wash time is artificially increased because some detergents need a long time to do their job properly.
So the answer is yes, but you would need to ensure only warm water entered the washing machine and ideally not too warm. If the cold water pressure dropped because of a problem with the supply or because of someone drawing off cold water elsewhere any delicate balance would be disrupted and potentially very hot water could enter the machine and damage delicate laundry. So without a thermostatically controlled valve it might be a bit hit and miss.
Are there any advantages to warm water being used? Potentially, it’s been suggested that rinsing in warm water may give better results.
hi there , my mum has just moved house and wishes to use her existing washing machine , however in the new house there is only one water supply tap for the washing machine but my mums washing machine has both hot and cold water valves . what do i do in this instance .
thankyou very much i hope you can help ,
kind regards ,
chris mitchell
Hello Christopher. You need this article is it possible to use a hot and cold fill washing machine with just a cold water supply?
A warm water connection to a cold-fill washing machine is no problem as long as an automatic mixer valve is used.
But one has to check the washing machine manufacturer’s manual, the max. allowed feed-in temperature should not be exceeded.
When checking the manual for this make sure it’s the washing machine’s max. temperature they refer, the pressurised hose might have a lower max. temperature. But this data can be found on the hose itself.
There are special devices available on the continental market, the Germans call them ” Waschmaschinenvorschaltgeraet “.
These can be programmed for temperature AND time, allowing for different feed-in temperatures within the same washing program.
The washing results with higher temperatures are better, rinsing with high temperatures takes the smell of chemicals from the detergent out, well, most of it.
Enzyme based detergents shoulnd’t be used above 50 degrees Celsius, they deterioate above this temperature faster than they can ‘catch’ the dirt, break down physically and making them useless for cleaing purposes.
Fabric softener is used cold (see manufacturer’s data sheet) to leave as much chemicals in the fabric, making it ‘soft’.
So when using warm water in combination with fabric softener most of this softener is flushed out and doesn’t stick to the fabric.
Compare the effect with hot candle wax poured in a bucket of a.)cold water and b.) in hot water: when these buckets are emptied the bucket with the cold water will have a thick rim of candle wax, the bucket with the hot water will show very little wax residues .
So if one want clean fabric then rinse warm. And not cold as most machine manufacturers have set their machines. But if one wants the smell of chemicals and an sticky touch (‘softness’) then rinse cold.
Here is such a device which allows warm feed-in and is programable, one can choose if smelly detergents or softener residues are be left in the fabric or not:
http://www.olfs-ringen.de
There are more manufacturers out there, since solar thermal energy is used widely (since about 10 years) several manufacturers are selling these ” Waschmaschinenvorschaltgeraete ”
The linked one above is since about 20 years available, as far as I remember.
Good luck!
PS
The electric energy consumption for a standard washing program is much less if the water is pre-warmed.
Here some samples of own readings, the machine a Bosch “Classixx 1400 Express”, 6kg
(WF02867GB) :
Program 30 degrees Celsius, ‘aqua plus’ (more water than standard), 1400 rpm, warm water feed-in temperature 22 degrees Celsius:
Electricity consumption: 302 Watt hours.
That’s less than 50 % compared to the same program using a cold feed. The A-rated washing machine ( the Bosch above) is now an A+++ machine energy-wise, something that isn’t available yet and propably will never be.
Similar result with a 60 degrees Celsius prgram, same setting as above , only the temperature set to 60 instead 30 degrees Celsius, feed-in temperature again 22 degrees Celsius:
Electricity consumption: 982 Watt hours
Still 30 % less energy consumption compared to a cold feed-in.
So a correctly set feed-in temperature would turn a cheap C-rated banger into an A+ machine (energy consumption).
And the cleaning performance will always be ‘A’ or better thanks to the warm/hot rinse.
@heinbloed
Both your comments above explains why rinsing in warm or hot water is better than cold. Now I know why my clothes feel so soft and look so clean. Warm water rinsing must also be performing extra cleaning, as well as dissolving the detergent out of the clothes? With each spin and next warm rinse, the detergent solution must be getting weaker as it gets more and more diluted and dissolved?
Maybe fabric conditioner in warm water helps to flush out the final remains of detergent much better?
WMuser wrote:
“Warm water rinsing must also be performing extra cleaning, as well as dissolving the detergent out of the clothes? ”
Yes, but the consequence that
” Maybe fabric conditioner in warm water helps to flush out the final remains of detergent much better? ”
isn’t the case. A detergent (here: the enzyme) is soluble in water, it needs no extra helper (here:fabric softener)to be rinsed out of the fabric. Water on it’s own is enough, it is the pefect solvent for washing detergents.
ref hot and cold fill i have not seenone mention of how near heat source is to W/machine ,first fill with cold is to protect soiled clothes from food and other stuff locking into the fabric.Second if the hot source is any distance from appliance depending of pipe run you could recive a slug of cold water before hot arrived negating this electricty saving considerbley,but the cooler mix would work for the washing cold +hot idea.
If you like to work out length and pipe size you can work out how much cold water before hot arrives .
Brianuk wrote:
“ref hot and cold fill i have not seenone mention of how near heat source is to W/machine ,first fill with cold is to protect soiled clothes from food and other stuff locking into the fabric….”
Well, it is protein what has to be looked at in this case, coagulating (“locking into”) at around 60-70 degrees Celsius.
No problem when feeding the washing machine with 30 degrees Celsius.
And nothing to be “worked out”, just set the temperature of the mixing valve at below that point, as said by previous posters before: set the temperature according to the capacity of machine AND detergent.
I use the full available temperature always when doing the hot wash, employing soap based detergent. No problem with protein stains, soap based detergents work even better the hotter the water is. Ask mom(smiley).