Solar Heated Water for Washing Machines with a Cold Feed only.

[Mickey]

I've recently changed my Washing Machine and find that the latest "high efficiency" models only have cold water feed.    This has set me back as I have a 30-tube HW Thermal system that's going fantastically well in the last few days.

In desperation I've connected the machines cold water input to the solar hot water supply.  All appears to be working as normal.  I kept my eye on electric consumption using Electricsave and hardly any power is being consumed QED.

Now I'm not a Washing Machine expert and would welcome any advice?  Am I doing any damage to the new machine etc?

Thanks Mickey

[billi]

hello

one other proplem is that  then ....the rinse program then uses the hot water as well  so you use more hot water than normal....

i think there are systems developped for solar hotwater with washing  , some sort of mixing device


regards billi

[Mickey]

Hi billi,

Thanks for that - at the moment I have too much Solar HW.  My top of the tank temp TSTU is getting over it's max setting of 65 degC.   My safety overload dump circuit is clicking-in to cool the system down.  When I had an older washing machine that had a hot water feed, being used most days, it drained off enough HW to cool the system.

I realise that I'm now using solar HW during the rinse programme but cost of electricity saved is way more than the price a few litres of water.

Also I'm worried that my new washing machine was using more electric just to heat the cold water from scratch. 

Mickey

[stephen]

dont know abou washing machines but you ould put a blend valve on the cold / ot water.  this will blend the hot with the cold so warm water can go in not hot. The control is a knob so turn it one way for hot and the other for cool.

stephen

[billi]

 hi Mickey

donot think (but not sure)  that a washingmaschine gets a problem with 65 degrees hot water , but perhaps your girfriends red Dress   

a dishwasher i know freaked out several times because didnot understand that the incoming water was so hot allready   ....

there are automated mixing valves or control systems  but costs monney upto 150 pounds


regards billi

[Paulh_Boats]

Mickey,

I had the same conclusion last year - modern washing machines/dishwashers are not suited to solar heated water.

Our Bosch machine takes hot and cold, works fine on a 40C program. But switch to 30C and it only takes cold water and heats it with electricity - the net result is that it uses lots of electricity when I have a tank of free hot water!     How crazy is that?

Likewise our dishwasher has a lot of residual water, so even though I plumbed it into the hot supply the free hot water gets diluted quickly and hardly warms up the machine...which then uses lots of electricity to get back up to temperature.

What we need are machines compatible with solar hot water systems....that actually use lots of hot water.

[Ivan]

Funny enough I was thinking about this recently too. Our washing machine uses a fair bit of electricity (presumably mostly for heating) even though we've always got solar-heated or woodstove-heated hot water available.

I have read similar comments to Paul's on a number of occasions. It seems that the washing machine draws only cold water for low temp cycles, a mixture for medium temperature cycles, and only hot water for the hottest 'whites' wash. I guess the emphasis is in ensuring that the wash temperature does not exceed the intended temperature range for the clothing inside. From a solar perspective, we are almost looking for the opposite.

I have heard that the solution is to wash the clothes on a hot 'whites' wash, so that it fills from the hot tap alone (presumably you could use an external mixer valve to set the actual temperature, as Billi suggested), and disconnect the internal heaters, so that the only heat comes from the hot water supply. Sounds like a good option to me. However, some new washing machines may not like this. My washing machine is currently out of action, due to a heater thermostat failure (has a wobbly and wont wash anything). Having done some research to establish what the error code means, I've found that it indicates heater failure, heater relay failure, thermostat failure - so if the machine can detect heater failure, it probably won't like having it's heaters disconnected. I wonder if there's a cunning solution?


Ivan

[billi]

hi

i heard of some people fill in the hot water in the maschine  with a watering can , befor they start to wash ......



billi

[Mickey]

Hi All - thanks for the postings.

The washing machine is the latest Hotpoint Aqualtis Range http://www.hotpoint.co.uk/macro/product.d2w/report?prnbr=AQXXD169 - it's a great device.  We are very pleased with it except the exclusive cold water feed.    I did look around and only the older obsolete machines, many now unavailable, still have a HW input.

I think the best options for now are - see how it goes with the Solar HW feed.  If that proves unsatisfactory then a mixer to keep the HW temp down to 30deg C may be the answer?

Incidentally, I've done some measurements and eventhough the TSTU temp is around 60degc the water initially after it's flowed around the house to the washing machine,situated down stairs,is appox 35degC.    As very little water is used the flow pipes do not have sufficient runtime to heat up to max.

Any other ideas welcomed -Mickey

[odbob]

I've read this thread with interest, my latest Bosch machine is cold fill only and it seems to me that manufacturers are let off very lightly with these so called energy ratings , mines an "A" rating ? why when it is unable to utilise heated water from alternative sources, surely in this day and age, machines should be getting better, not worse

[David]

There are three claims to do with cold fill only washing machines.

The first is that modern machines use so little water that no hot water would be drawn off into the machine. Thus the energy involved in heating it would be wasted. This claim probably relies on a "typical" UK house with a long run of 22mm pipe  from an upstairs airing cupboard to a washing machine in the kitchen.

The second is that as the water will be heated by an electric element in either case it makes more sense to heat the water in the machine when needed. This claim relies on the water being heated by electricity at the same rate in the machine and in storage. There may be some houses like this in the UK, but not many.

The third claim is that modern washing powders work best by being warmed up to a reasonable temperature from cold and their cleaning performance is not as good if hot water is applied directly.

What they never mention is that avoiding UK specific hot and cold machines saves the manufacturer some money.

[Phil]

Hello,
  I have an older Bosch WFM 3030 with a hot and cold input I have tee'd the hot pipe from my thermal store and plumbed it into both hot and cold inputs.  we then always set the machine to wash cold and adjust the water temp manually with the thermal mixing valve from the store.   We have been doing this now for 2 years with no problems, OK its not perfect but if you have nothing better to do you can even rush upsatairs at the right moment  and turn down the temp for the rinses,  Mr Bosch seems to be happy  and I need to get out more.    

[dhaslam]

The older washing machines with hot and cold inputs only uses hot water input for wash settings higher than 60C, they didn't actually mix the water as they should have.   Because  washes above 60c are rarely used now they just eliminated the hot feed.   

[northern installer]

draws only cold water for low temp cycles, a mixture for medium temperature cycles, and only hot water for the hottest 'whites' wash. I guess the emphasis is in ensuring that the wash temperature does not exceed the intended temperature range for the clothing inside. From a solar perspective, we are almost looking for the opposite.

I

Funny enough I was thinking about this recently too. Our washing machine uses a fair bit of electricity (presumably mostly for heating) even though we've always got solar-heated or woodstove-heated hot water available.

I have read similar comments to Paul's on a number of occasions. It seems that the washing machine have heard that the solution is to wash the clothes on a hot 'whites' wash, so that it fills from the hot tap alone (presumably you could use an external mixer valve to set the actual temperature, as Billi suggested), and disconnect the internal heaters, so that the only heat comes from the hot water supply. Sounds like a good option to me. However, some new washing machines may not like this. My washing machine is currently out of action, due to a heater thermostat failure (has a wobbly and wont wash anything). Having done some research to establish what the error code means, I've found that it indicates heater failure, heater relay failure, thermostat failure - so if the machine can detect heater failure, it probably won't like having it's heaters disconnected. I wonder if there's a cunning solution?


Ivan

[northern installer]

oops wrong button!
what I was trying to say was,locate the sensor responsible,set it up with the temperature you want the brain to think its reading,measure the resistance,now,replace the sensor with a resistor of that value.....worth a try?