Pumped Thermostatic Mixer Shower Plumbing Part 2

[r.rain]

Hello All

Been looking at my HW Cylinder in prep for installing a Thermostatic Mixer Shower and at the top I have a feed which has a stop c*ck attached that goes to nothing. If I open the stopcock water flows. Could I use this output as opposed to fitting an essex flange (What a funny name that is) The feed is basically split into 3, 1 pipe goes to the cold water tank and sits above it, I think this is an expansion pipe? and the other goes to the hot water taps, the third to the stopcock as explained. Should I stick to plan A and install the flange. I'm thinking here that if someone turns on a hot water tap during a shower this could interfere with the flow into the shower. That said I would be buying a twin impeller pump so would this negate the effects of this?

TIA

Richard

[Aidan]

The other possible problem is that the hot water outlet usually contains small air bubbles, which usually go up the open vent pipe or out of the HWS taps. The air is dissolved in the cold water and are released when the water is heated. Connecting the pump to the HWS outlet pipe might allow these bubbles to accumulate in the low level pump & cause an airlock.

I'm fairly sure that your proposal wouldn't comply with the pump maker's installation instructions and could invalidate the guarantee. You can usually get the instructions off the web sites. I'd plan on fitting an Essex/Surrey/Warix flange.

[Ian_m]

I think I said "do it as per the instructions and its fine". I have encountered all type of "other" pumped installation, all done to save effort, but all had to be undone as they produced "crap" showers. Why buy a £200-£300 Techflow pump, decent mixer valve £200-£300 + all the other required shower fittings and then balls it all up in incorrect plumbing.

[r.rain]

You certainly did, just double checking seeing as I already have pipe work I can tap off from. I will fit the flange......

Cheers

Richard