Shower pump comes on when it shouldn't!

[dylan_diy]

Hello I'm after some advice. We have a non pressurised heating system for our hot water (and central heating). A gas bolier but not combination so the hot water is stroed in a tank. A few months ago we had a new shower installed that feeds from the hot water tank but is pumped via a 3 bar shower pump.

We recently have been having problems wherby if you switch the tap on (more so the hot I think but it is tricky to tell as all our taps are monoblock mixers), when you are finished and turn the tap off the shower pump all of a sudden kicks into life. Now this would be fine if it were just a single short burst but it kind of pulses on and off and sometimes the only way to stop it is to kill the power (via RCD). Does it sound like a fault with the pump or the way it has all been plumbed in - it looks to be a very simple methood of feed from tank into pump - out from pump to shower....

TIA

Dylan

 

[Diyisfun]

Its the pressure switch on the pump, probably happens only if you turn the water off quickly.
I dont know the fix only the reason.

 

[Terrywookfit]

Do you have any dead legs of pipe !!

This is normally caused by air trapped in the pipes!!

Air will compress causing the flow switch to operate!!

 

[dylan_diy]

Dead legs??

How do I clear the air?

 

[Terrywookfit]

Unused pipes that are capped !!

Make sure they are full of water !!

 

[dylan_diy]

There are no dead legs on the "circuit" that supplies the shower. There is one cold feed dead leg that used to supply the old electric shower but this has water going right to the cap (an inline valve). Any further tests I can do or look for?

 

[wms]

had the same prob a while ago. try a non ret valve on cold supply to pump this cured it for me.