baxi 105e pump prob

[garlicbread]

neon indicating fault on pump or low pressure, the pressure was on the low side so i have topped it up to 1.5-2 bar still get the fault. i have opened the air valve on the pump which did nothing, any advice much appreciated or am i looking at a new pump.

 

[kevplumb]

delete

 

[bengasman]

I would test the pump first.

 

[petit_pablo]

Check pump is running then check the pump flow switch. Should activate the microswith if the diaphragm is ok, if not diaphragm is probably holed

 

[kevplumb]

View media item 14783

 

[garlicbread]

cheers for the info, can you manually activate the microswith and how would i go about testing the pump

 

[petit_pablo]

cheers for the info, can you manually activate the microswith and how would i go about testing the pump

To check pump, unscrew the cap from the middle and see if its spinning inside. If not, you need to check its getting 240vac from board.

You can manually make the flow switch by removing the microswitch and making the contact with a screwdriver to test it but dont permanently override it.

 

[garlicbread]

cheers for the replies it helped in my fault finding, i checked voltages to pump all ok, ended up narrowing it down to the micro switch on the diverter valve, it seemed to be stuck in position, managed to get it free and cleaned some limescale from around the top and now the boiler is back up and running, even with hot water constantly. (might replace the diaphram though or at least check it tomo. quick question how do i"drain the primary circuit" so i can replace the diaphram?
thanks again

 

[davebgas]

quick question how do i"drain the primary circuit" so i can replace the diaphram?

Right hand side of the pump is a white drain point pointing down.... stick a tube on it into a bucket, shut the flow and return isolations off underneath the boiler, open drain valve.

 

[garlicbread]

cheers very helpfull

 

[davebgas]

Press my 'thanks' button fella!

thank you very much-ski

 

[garlicbread]

thought the prob was solved, but its back, i can get the boiler running again by pushing the contact down on the diverter valve assembly so when the boiler kicks in it pushes it back up and activates the micro switch. But after several hours i get the warning light again, "pump 0r low pressure"
do you think this is due to the diaphram wearing away and needs replacement (before i take it all apart)?

 

[mickyg]

you said before that you cleaned limescale from the switch, which suggests that its leaking from the gland nut. If i were carrying out this job for a customer, I'd replace the diaphragm, microswitch and gland nut in one go, for the sake of what they cost.

Edit: looking ar diagram, looks like you might have to buy the whole housing.