baxi 105e changed pump still got a pump fault showing

[lee spencer]

hi, firstly a bit of back ground. a couple of weeks ago the hot water pipe under our both blew off (due to the chap who fitted the bathroom before we bought the house not tightening a compression fitting properly) anyway this led to the hot water pumping out under the bath for around 20 mins before my wife could shut it off, I was 56 miles from home trying to talk her through it on hands free, needless to say our ceiling is now in a bad way. fast forward a few weeks and one morning we had no heating or hot water. checked the boiler and the pump / pressure neon was flashing, pressure was and still is good so deemed it to be the pump.
purchased a new pump, fitted it, reset the boiler and the fault was still on. now the weird bit, if I turn the boiler off and set it to continuous heating, upon turning it on it works fine, we have hot water and heating, change it to timed and the fault light starts flashing and we have neither.
after going online a lot I reckon its the diaphragm that works the micro switch, any other ideas??
thanks in advance
lee

 

[ianmcd]

yes it could be the diaphragm, but also check where the sensing pipe enters the diverter valve, it is common for this small orifice to become blocked, a very easy job to do

 

[lee spencer]

yes it could be the diaphragm, but also check where the sensing pipe enters the diverter valve, it is common for this small orifice to become blocked, a very easy job to do

Thankyou, I will try this tomorrow when I'm back from site. cheers!!!