Installing mixer shower

[Alanmelon]

Any plumbers out there? I've just had a new combi condensing boiler fitted, but unfortunately it's not compatible with my existing mixer shower. Rather than fork out another extortionate installation fee, I've managed to source a replacement which should be easy to install as it's very similar to the existing one, but I obviously need to switch off the water and supply from boiler.

Is this as simple as switching the combi off, then turning off the water at the stop cock, then when done just reversing the process, or is there some convoluted start up process which I need to adhere to?

The boiler is a Worcester Bosch 28i Junior.

[Raistlin]

Should be as simple as turning off the boiler and then turning off the stop-cock, you'll probably need to let the pressure out of the system by turning on some downstairs taps until they stop running as well.

Starting things back up should be as simple as reversing the process. If you've just had the boiler installed you should have had a manual with it as well, have a read and see what that says before you do anything though.

[Vlad_Dracul]

Are you saying that you previously had a combi with your existing shower and youve just had a new combi fitted? If so,if the shower was compatible with your old combi then whats changed? A combi is pretty much a combi and the condensate bit is only to do with recovering extra heat from products of combustion to pre heat incoming air or water streams..

Originally Posted by Vlad_Dracul

Are you saying that you previously had a combi with your existing shower and youve just had a new combi fitted? If so,if the shower was compatible with your old combi then whats changed? A combi is pretty much a combi and the condensate bit is only to do with recovering extra heat from products of combustion to pre heat incoming air or water streams..

I'm guessing the previous boiler was not a combi, as some mixer valves & shower heads are designed to work at lower or unequal pressures - presumably why Raist needs a different design to work with the higher / equal pressure you get from a combi boiler.

http://www.diydoctor.org.uk/projects...ght_shower.htm

Regarding the fitting, as he surmised, turning the boiler off, shutting the stop-cock & draining the upstairs pipes sufficiently to allow the new mixer/head to be fitted should be fine.

If possible I would recommend fitting a thermostatic mixer, we have one on our shower, using the same make of boiler & it is brilliant - but obviously a bit more expensive...