baxi 105e instant dhw problem

[gest1221]

Baxi105e instant dhw will take up to 5 mins for the led to light up and fire the boiler if I turn the preheat selector no change but if I repeatedly turn the selector on to off it will light the led and fire the boiler new PCB fitted 3 months ago CH working OK is this a duff board not recognizing the dhw is in demand or a possible diverter valve or micro switch problem

 

[Gas2Air]

Diaphragm.

 

[ianmcd]

As already advised the DHW diaphragms are very common to go faulty on these very easy to test and very easy to replace and they are not expensive so you will be hoping that is all that is wrong with it

 

[Agile]

I would be examining both the microswitch and to see if its being reliably actuated by the diaphragm.

Tony

 

[gest1221]

Thanks for the speedy replies had not considered the diaphragm the last one that I changed a few years ago registered the demand for hot water but failed to fire the boiler in this case the boiler is not recognizing the demand for hot water as soon as it does the boiler fires will fit new diaphragm and see if it fixes the problem thanks again

 

[gest1221]

Right this is a new one on me it was not the diaphragm but it was to do with the diaphragm the small pipe on the diaphragm housing was blocked so it stopped the micro switch working properly cleared the blockage put it back. together and works fine now thanks for all the help pointing me in the right direction