Bungalow- will this work? hot supply to shower pump in loft

[Battyboy]

Hi,

Im installing a new thermostatic shower and pump on a gravity system in a bungalow.

Getting an independant cold feed from the CWSC to the shower is no problem. But, the hotwater tank is in the kitchen. So to supply the independant hot feed, i was planning on teeing off below the vent pipe branch then taking the pipe up into the loft, into the pump, then down into the bathroom to the shower.

My dillemma is the destructions on the pump are saying not to run the hot feed any higher than the height of the hot water tank. Now i can understand they are concerned about air being brought into the pump, blah, blah, but i will be teeing off below the open vent branch before i take it up and acrross to the pump.........

The hot tank is already raised, its almost touching the loft space anyway, but i just wanted some opinions as to whether you think the manufacturers are being OTT as usual or whether i should really not run the hot feed up into the loft, then pump then shower.........??

Also, do you reckon i should run both hot and cold in 22mm, reducing them to 15mm upon entry to the pump or just use 15mm all the way??

Thanks guys....................

 

[Breesey]

It would work. Run it in 22 and use a surrey flange.

The manufacturer is setting out the conditions that should be complied with in the event you need to make a warranty claim. If you don't do what they say they wont honour the warranty, it doesn't, necassarily,mean the pump won't work.

 

[Bon]

Provided the header tank for the hot water cylinder is above all the pipework and pump, it should work as the water will gravity-flow and therefore the flow switch in the pump will operate.

If not you'll need a negative head pump.

Also, make sure your shower is suitable for use with a mains cold feed and pumped hot feed.