Hot & Cold garden tap

[ar75]

Hi all, need advice on the followig:
I intend on fitting a garden tap which could supply both hot and cold water.
this would be achieved by taking a feed from both hot + cold pipes under kitchen sink through outside wall then add a check valve? to both feeds before they meet at a T which would then connect to the garden tap.
I already have the garden tap kit which consists of a self cutting thingy and a length of hose to run to the tap, however, what I'm thinking is to use another self cutting thingy for hot water pipe then changing from hose to compression fittings on exterior.
The reason for doing all this is so I can have cold water for garden use and the option for hot/warm water for pressure washer use, but before commencing I thought I best seek advice first.
My main concerns are if this could have a negative effect on either the boiler which is a Potterton Promax Combi HE Plus, or on the pressure washer which is a Karcher K3550.
Any advice/guidance on any of the above greatly appreciated.
Thanks in advance,
Adrian.

 

[gas_man_gaz]

personally dont see the need for a hw supply but if ya going to do it id fit a 2nd tap just for the hw

 

[John506]

As above.

Yes fit a check valve on each branch, fit it inside the building along with an isolating valve.

If you want warm water, I suggest a blending valve inbetween each hot and cold tap, with a 3rd tap for water at your desired temperature. Dont forget more check valves though.

 

[ar75]

Thanks for your replies, & sorry for the first longwinded post, but in short what I'm trying to acheive is in effect a mixer tap i.e one tap with controlable hot & cold feed running to it. The problem with having a seperate hot tap is my pressure washer states max temp of 40C, so I would have to turn temp down on boiler each time I used it, affecting the hot water taps in the house. A single tap which could give cold/warm/hot would suit better as its also at the front of the house.
Feel free to advise otherwise if I'm missing something, or if this sounds o.k what bits would work best?
Thanks again,
Adrian.

 

[kevplumb]

i'm wondering if with a pressure washer and a mixing valve you will get enough flow through the boiler to fire it

 

[kirkgas]

i have fitted a 2nd outside tap for hot water, to fill the kids paddling pool and also for the pressure waasher, TBH the temp is never that high at the washer due to the flow, as the flow is high at the washer it doesnt stay in the boiler too long

 

[ar75]

i have fitted a 2nd outside tap for hot water, to fill the kids paddling pool and also for the pressure waasher, TBH the temp is never that high at the washer due to the flow, as the flow is high at the washer it doesnt stay in the boiler too long

I see your point, hadn't thought of it that way, I suppose 15 metres of hose would lose some heat also.
Thanks,
Adrian.

 

[ar75]

i'm wondering if with a pressure washer and a mixing valve you will get enough flow through the boiler to fire it

Could I not have full flow on hot side and use cold to cool, have good pressure on both hot and cold in the house?

 

[muggles]

You may have good pressure but do you have good flow? They are not the same thing and the difference is important in this situation

 

[ar75]

You may have good pressure but do you have good flow? They are not the same thing and the difference is important in this situation

This is where my lack of knowledge for basic plumbing gets the better, pressure,flow, why can't things be straightforward? But surely I'd have the same flow outside as I do inside? When I open the hot water tap at the sink the boiler comes on, why would it not when I open a tap outside?
Sorry if I'm being stupid but as you've probably gathered I'm not a plumber!
Thanks again for all replies,
Adrian.

 

[David937]

i'm wondering if with a pressure washer and a mixing valve you will get enough flow through the boiler to fire it

Dunno if this helps but the Karcher has a flow rate of 7 litres/minute.

 

[ar75]

Thanks David, the penny has dropped at last!
Yes, my karcher states max flow rate of 420ltrs per hour = 7ltrs per min.
When the hot water tap is fully open the flow rate is approx 12.5ltrs per min, and yes the boiler does come on well below 7ltrs per min.
It now makes more sense to me to have 2 seperate taps rather than my
"mixer" tap contraption thingy
Thanks again to all who replied & sorry for being a bit of a numpty
I'm sure I'll get there in the end!
Adrian.