Mixer Shower off bath tap supply?

[Zoltan G]

I need to add a shower to my existing bathroom and think a mixer shower is the best option (have a fairly up to date combi boiler). Can I run supply pipes from those that feed the bath taps to use as the shower's inlet supply?

 

[Bahco]

Can't see why not if you have a combi and have reasonable water flow

 

[Zoltan G]

Thanks Bahco. I do have a combi but I'm not sure what the pressure of the system is like. I gather that I should try and ensure that the pressure of the incoming hot supply equals the pressure of the cold water supply. How do I measure the pressure? And if the pressure of the cold feed is greater than the hot (which I would imagine to be the case) can I put some sort of tap or valve on the cold feed to reduce the pressure?

Advice welcome!!

 

[gas4you]

You could always put a pressure reducing valve on your cold main inlet if you have high cold mains pressure. This would balance your domestics.

 

[Zoltan G]

Thanks Gas - I looked at a Mira combiforce installation guide on their website. I wasn't expecting it to be 52 pages long! It did emphasise throughout that the pressures of the two inlet supplies (hot and cold) need to be roughly equal. Thanks for the pressure reducing valve suggestion - but how do I measure the pressure of each feed in the first place?

 

[gas4you]

not quite sure what you mean. Measure mains incoming pressure with pressure guage fitted to cold tap? Set pressure reducing valve to less than incoming pressure. eg if incoming pressure is 4 bar set prv to 3, this will give you 1 bar excess to let the prv balance correctly when other taps are turned on.

Sorry if I have mis-understood your question!

 

[Zoltan G]

Thanks again. No I don't think you've misunderstood my question at all! I think though that I am not in the least bit qualified to ask them in the first place

I will measure mains pressure like you say. Thanks again