Shower pump cold feed dilemma!

[chris_o]

Afternoon people. I do bathroom refurbs for a living and have fitted many Stuart turner pumps the ‘correct’ way. I.e. dedicated 22mm feed from the cws tank, and Surrey/ Essex flange from the cylinder.

However this current job is a headscratcher. Big building that’s been divided up in to apartments in the 80’s. Open vent cylinder set up with cylinder in airing cupboard, however the cold tank is a long way away up in another hatch in a stairwell. All pipe work inaccessible. At a loss as to how to feed the pump with cold. There is a cold main feed that is useable in airing cupboard if need be.

Question is as I’ve never done it, is it a big no no to tee off cold feed to cylinder for the pump? Another option I just considered was to install a new cold water tank in the quite large open space above the cylinder and feed the pump from that? Has anyone got any clever ideas? Thanks

 

[johnny2007]

Feed from main and install pressure reducing valve to match hot water pressure?
Not a plumber, so wait for other opinions.

 

[chris_o]

Thanks. Have been reading up on the option but unsure whether it is really viable or not. I’ll have to scrap my own idea of a new cws tank in airing cupboard as I can’t sort an overflow to anywhere!

 

[foxhole]

I think if mains cold then only hot needs a pump .

 

[Exedon]

We have done a few properties (my own included) where we have fitted a pump on hot to match mains pressure.
Obviously needs non return valves fitting but works well we always use Stuart turner monsoon pumps.

 

[chris_o]

Great thank you, this is filling me with more confidence before my stress filled work day is over. I will test mains pressure then and if need be fit a prv on the mains feed to the shower. I was after a 2 bar pump so would obviously just need to set the prv to 2 bar?

Where would you ideally site the non return valves?

Thanks!