Air pressure switch

[irose]

Hi
I have an Ariston Genus 27MFFI combi. Recently it has developed a problem where the air pressure switch does not always operate. What will happen is the boiler will light then after a short time, the burner will go out but the fan still spins. Then the boiler will re-light again. This cycle is repeated. If, however, I remove one of the spare flue covers in the top of the boiler all works OK. By removing this said cover, more air is drawn in. Nothing appears to be blocked in the flue. Could it be that either the air pressure switch is faulty or the fan is not expelling enough? Any help appreciated.

 

[kevplumb]

1 dont mess with a room sealed apliance flue
2 it probably needs a service

 

[croydoncorgi]

Symptoms suggest insufficient airflow through boiler. By opening the case (in effect) you've reduced the flow resistance and so the airswitch closes.

But like the man said: Don't mess with roomsealed appliances or their flues. Especially if you don't know what you're doing - as you clearly don't!