Hot water for jetwash

[PThomas]

Hi Guys

I have standard outside tap plumbed in under my kitchen sink. Drive and garage are around 12m away from the house.

This time of year its a pain to keep the cars clean and to remove as much salt as possible. I would like to use some of the hot water stored in my hot water tank (Mains pressure hot water) to feed the jetwash.

I was considering using a thermostatic mixer valve under the sink plumbed into a spare hot water take off (Left from an old washing machine) and the existing cold supply - then feeding this to the outside tap. I would ensure there was still a hot shut off valve as it wouldn't be needed for watering the garden

Does this sound feasible?

Any alternative ways? (Maybe having a electric shower unit mounted on the wall in the garage and having hose in/out plumbed into it?)

Any advice/suggestions gratefully received!

 

[muggles]

First thing you need to do is check your pressure washer will accept hot water, you might just bu99er it up.

If you do go for mixing the hot and cold you need to make sure there's adequate backflow protection to prevent hot water flowing into the mains. You'd be better off to just put in a second outside tap and run the pressure washer off pure hot water, if it'll take it.

An electric shower or instantaneous water heater wouldn't keep up with the required flow rate and would just run cold all the time.

 

[HERTS P&D]

I have an outside hot tap and used a top end Karcher unit, which lasted about 2 weeks before it broke. It was fed from a combi with very good pressure.

Pressure washers can only use cold water. As I found out.

Andy

 

[TicklyT]

......An electric shower or instantaneous water heater wouldn't keep up with the required flow rate and would just run cold all the time.

...Until you release the trigger on the washer, then the heater will overheat and cut out.

 

[David937]

My Nilfisk unit runs fine on hot water, it has an upgraded lance and hose though...

 

[PThomas]

I have an outside hot tap and used a top end Karcher unit, which lasted about 2 weeks before it broke. It was fed from a combi with very good pressure.

Pressure washers can only use cold water. As I found out.

Andy

Maybe depends what temp water you fed it on? Even the basic Karcher models will accept 40 degree C hot water....

 

[PThomas]

First thing you need to do is check your pressure washer will accept hot water, you might just b****r it up.

If you do go for mixing the hot and cold you need to make sure there's adequate backflow protection to prevent hot water flowing into the mains. You'd be better off to just put in a second outside tap and run the pressure washer off pure hot water, if it'll take it.

An electric shower or instantaneous water heater wouldn't keep up with the required flow rate and would just run cold all the time.

Yes it will thanks. Max 40 Deg C, which is why I thought a mixer unit may work....

 

[PThomas]

Would a standard 15mm mixer unit like this:-

http://www.screwfix.com/p/pegler-prestex-tmv2-thermostatic-mixing-valve-15mm/26411

Be suitable for my needs?
I could pre-set the max temperature and I presume it must have some sort of back-flow prevention otherwise the cold water could overpower the hot or vice-versa.

 

[Corgigrouch]

I have a hot and cold tap outside and use the hot tap fed off my combi on my hose for washing the car... great on a cold day....Not at all sure that I would want to use a pressure washer on any of my vehicles though.... I wouldn't reccommend using a pressure washer on the hot supply off a combi as the sudden water hammer of turning on and off can damage the guts of the washer or even the plastic guts of the combi.....

 

[PThomas]

I have a hot and cold tap outside and use the hot tap fed off my combi on my hose for washing the car... great on a cold day....Not at all sure that I would want to use a pressure washer on any of my vehicles though.... I wouldn't reccommend using a pressure washer on the hot supply off a combi as the sudden water hammer of turning on and off can damage the guts of the washer or even the plastic guts of the combi.....

I don't have a combi - its a a pressurised hot water system with a hot water tank.

 

[Nige F]

Pressure washers can only use cold water. As I found out.

Andy

You could`ve asked your old "dad" here on DiyNot. . P.S do you think the cop on " Whitechapel " looks like A. Steptoe`s love child

 

[Corgigrouch]

I have a hot and cold tap outside and use the hot tap fed off my combi on my hose for washing the car... great on a cold day....Not at all sure that I would want to use a pressure washer on any of my vehicles though.... I wouldn't reccommend using a pressure washer on the hot supply off a combi as the sudden water hammer of turning on and off can damage the guts of the washer or even the plastic guts of the combi.....

I don't have a combi - its a a pressurised hot water system with a hot water tank.

Yes, I am aware of this but loads of other folk here will think that a hot tap outside is a good idea.... Some of them will have a combi