Shower pump pulsing

fraggleKFC_2

Hi, looking for a bit of advice....

We had our bathroom done a few months ago, part of which required a pump to be fitted for sufficient pressure for the shower.

The pump is fitted right next to the cylinder so all hot water for the house gets pumped.
For the last few weeks when a tap is run or the shower used, the pump kicks in as normal but when tap is turned off the pump continues to 'pulse' on and off, ie 2 secs on, 2 secs off for anywhere up to 2 minutes.

This obviously shouldn't happen and I was worried about damage to the pump with it running dry. I contacted CS and was told it wasn't damaging the pump, the issue was caused by air getting into the pump somehow. I was told short term to 'purge the system' which I do not know how to do, long term fit a low pressure non return valve to the outlet side of the pump to stop air getting into it.

Does this sound right? I bought the valve today but am a bit wary of fitting it as it might well reduce the pressure.

Anyone experienced similar or have any thoughts on this?

Thanks

Fraggle

jayyar66

Although it won't damage the pump, you are quite right, the pump shouldn't pulse as it does. This undoubtedly will be caused by air in the hot water pipework. . . . somewhere! To purge the hot pipework, simple open each hot water tap, one at a time, and allow them to run for, say, 15 - 20 seconds each. This should allow enough time to clear any air.
Just out of interest, have you ever found that you've run out of hot water? For example, has the shower ever started to run cool after a prolonged shower?