ferroli 77FF combi

[waterpistol]

hi there, i have encountered a problem with my combi boiler; basically i have no hot water and no heating. but, after replacing the air pressure switch (on a plumbers diagnosis) the problem persists. i noticed that when the boiler started to deteriorate there would be a clicking noise before the burners would fire up, then the length of time between the clicking starting and the burners firing up got longer till no more clicking and no more firing up. also when i came to relight the pilot light recently the ignition switch didn't work at all and i had to use a lighter to re-light it.

having examined the air inlet/outlet tube i notice there are no leaks or holes and when i suck on the tubing the air pressure switch clicks into operation and the burners fire up, so i am thinking it's the brain that's at fault not the air pressure switch but hoping it's not going to be too costly.

i also noticed that the upstairs taps, which are a metre from the boiler never had any trouble with being supplied with hot water but the downstairs kitchen taps were a lot less reliable...

ok, sorry to write an essay. cheers, ben.

 

[Puddle]

Well it sounds like the fan,if working ok,ie not slow
you could remove the fan and clean the drum blades with a tooth brush
make sure dust does not get in fan motor.then replace fan.operation should be ok

 

[waterpistol]

Well it sounds like the fan,if working ok,ie not slow
you could remove the fan and clean the drum blades with a tooth brush
make sure dust does not get in fan motor.then replace fan.operation should be ok

the fan was recently replaced with a new one... so i am pretty sure the fan is not to blame... although is there a chance it wasn't installed properly? i.e. is it the fan that sucks the fumes out of the heat exchange vent? cheers!

 

[stevetheplumber]

if it fires up when you operate the airflow switch it definatly not the pcb as some one has said clean fan and the maybe a venturi in the flue which needs cleaning

 

[Puddle]

It is difficult to fit the fan incorrectly but do double check the gaskets are ok were flue elbow meets boiler and that outlet gases are not mixing with air intake
The next thing to check would be the flue itself,make sure outer air intake section is not blocked ,restricted with silt,check flue terminal clear and not damaged,then I can not remember if a restrictor is fitted inline in one of the tubes to the air presure switch,if so remove and clean out,check the venturies the tubes fit on to are clear