Grundfos Shower Pump Not Turning

[billsy]

Hi guys

Do we have any shower pump experts? I've had a Grundfos Amazon 2.0bar shower pump installed in the ensuite for about 18 months. It has only been used occasionally.
For the last few months the pump has faild to turn when called for but turning the shower off and on a few times will normally make it work but not today, it just wont pump. The pump does make the same activation sound every time the shower is turned on weather it pumps or not. But the shaft is not turning now.

I have removed the none return valve from the shower head.
I have checked both inlet filters at the pump which are clear.
I have checked both flow sensors. They are working fine. Which had to be working as the pump is always activated (just refuses to pump).

Does all this sound familiar to anyone? My guess is the motor is goosed.

Please help

Many thanks

 

[ALCPlumbing]

Sounds like the flow switch or capacitor has gone or is on the way out. Obviously the flow switch is the part that senses the flow of water and activates the pump and the capacitor actually gets the impeller spinning. When it's not spinning yet the shower is open can you hear a sound that suggests the pump is trying to start, like a humming, or is it just dead as it would be with the shower shut off. If it's the latter I would guess at it being the flow switch. Someone here will be able to give you a definitive answer. Both parts are reasonably cheap and quite easy to replace.

 

[billsy]

Thanks for the reply

I have checked both flow sensors and they are working.

When I turn on the shower, there is a thump from the pump (this is normal I think) and a humming noise but it is not turning.

I will test the capacitor next but I think the thump is an indication that the cap is functioning. Please correct me if that's incorrect.

Cheers