Additional ensuite, 2 existing bathrooms with combi boiler?

[timbeam]

Hi,

I already know that the ideal solution is not a combi boiler for this amount of bathrooms and that a separate hot water tank would be much better. That being said, I just want to know whether what I want to do will work.

I have a Worcester Bosch greenstar 37cdi in the cellar and want to install a new ensuite in the loft conversion. As stated in the title, the house already has 2 bathrooms. When both showers are in use, flow is reduced but still adequate.

What I would like to know is 1) with the boiler being in the cellar and the new ensuite being 3 floors up, will flow/pressure be an issue? 2) Would it be possible to use the new ensuite shower while one of the other showers/baths are being used? Or even better, all 3 in use at the same time, without being reduced to an unusable trickle?

Thanks for your help, all advice and experience is greatly appreciated.

Tim

 

[terryplumb]

Combi boilers will not supply 3 dhw outlets at the same time ,with a good flow rate.

 

[steve32]

Electric shower always handy for when the combi breaks down.
Unless you've got good water pressure unlikely all 3 will work at the same time.

 

[timbeam]

Cold water pressure is 60psi.

I should have said that it's impossible to get an electric cable to where I want the shower. Otherwise, that would've been a good solution.

 

[Hot&Cold]

Cold water pressure is 60psi.

That is a reasonable number but remember your combination boiler is preset to deliver hot water at a constant controlled rate,(example) 13.5 l/min with the cold water temperature raised by 40oC.

The thermostatic bar shower mixers i fit (Bristan) need 7 l/min of hot and cold of balanced water pressure(they have flow regulators), so your 2 showers could be just about working and adding any more hot outlets will have a severe negative effect when used together.

Also consider the mains water inlet pressure could change and your existing plumbing could be 'just about working' who knows ?

best get a plumber in to see what can be done,

 

[timbeam]

Like I said above, the existing two showers work satisfactorily together at the moment. I can cope with the fact that I can only use 2 simultaneously if that is the only issue.

My main concern is that the boiler is in the cellar and the new shower will be in the attic. Do you foresee any problems with the hot water because of this or shouldn't it be a problem?

Thanks again for the input.