Iflo Shower Pump Problem

[robba]

New to this, hopefully someone out there can help! I have a 1.5bar twin impeller Iflo variespeed shower pump, it was working fine for 18 months, but started to leak from the hot input at the valve. Called the plumber who fitted a new washer. He subsequently spent an hour and a half trying to get it work again!

The pump refuses to switch on when the shower is turned on, however has now started coming on briefly (for about a second) when any other hot tap in the house is switched on. It never used to do this.

The pump is in the airing cupboard, the hot feed is from a pipe going into the hot water tank, the cold is feed from a tank in the attic. The cold output goes under floorbords to the shower the hot goes up to the attic along about 6ft and down into the shower.

Any ideas, could it be an airlock?

 

[seco services]

when you turn shower onto fully hot will pump start ?
if pump won't start is their any water flow from shower on fully hot only ?

 

[robba]

thanks for reply
No the pump won't start on fully hot and there is no water flow on full hot, and only a weak flow on cold?

 

[seco services]

sounds like the pipework is full of air.

try removing the showerhead and lay the hose in the bath.

do you know if the hot pipework in the loft has any bleed vents on it ?

try it on fully cold with the hose in bath and shower head off