New shower pump fitted but low cold water pressure, help?

[Kyezer]

Hi all,
Just fitted a new 2bar shower pump as the last one (a Mira PPT3 was knackered - it decided to start running all by itself and wore itself out; was noisy for ages before though) and it seems that there is low cold water pressure at the shower head. **note - the cold water pressure was poor with the old pump; just assumed this was normal until now**

The new pump is from Wickes, brass type and is good for 2bar. It's mounted at the mid height to the hot water cylinder and takes off the cold from the loft water storage tank, which I reckon is about 4-5ft above the pump. There is a run of about 3m from the pump to the shower (a Mira Excel mixer shower and head); hot water pressure is very good - much better than the old pump, yet when the mixer is turned down to cold only it trickles out and obviously the sensor in the pump shuts off the pump as it thinks there is no supply. Looked in the loft and cannot see any obvious leaks. Pipework seems okay.

I guess it could be;
- pump not mounted low enough
- pump is faulty
- mixer is knackered (how do I tell?)
- blockage in the cold water pipe (although doubtful I think)

anything else obvious?

Any idea why only the cold water pressure is low?

 

[mysteryman]

Investigate the cold supply to/from the pump. Could be a bit of debris in the pipework.

 

[ChrisR]

COuld also be in the filter on the inlet to the mixer, if it has one.

 

[Kyezer]

Well after a few proper uses it seems to be okay; didn't say on the instructions about maybe running it in, but seems alright so fingers crossed.
Thanks!

 

[HERTS P&D]

Normally when we fit a pump, we take off the shower head and lay the shower hose in the bath. Then turn on the hot water and then turn to cold. This normally removes any air locks - which I think you had.

Andy