Chuffing Baxi Solo 2 Boiler

Evening all,

I have recently been having some trouble with my Baxi Solo 2 50 PF boiler. I have cover for it through Scottish Power and eventually after numerous visits by their engineers and a new fan, PCB, pressure switch and gas valve the problem was solved.

The boiler is now working well except for one odd issue. Approximately 5 mins after the boiler switches off (i.e. after the timer has switched it off) it suddenly makes quite a loud chuffing noise. It just doesn't chuff continuously, it only does it the once - 'chuff'. To me it sounds like a sudden release of pressure, maybe air. I cannot smell any gas so I am assuming it is not that.

The noise is similar to when the main gas burner ignites, but is quite a bit louder (we can hear it from upstairs). I wondered if it might be that the new gas valve was faulty and wasn't closing properly allowing the flame to continue burning until eventually it extinguishes with a pop, however I cannot see any flames through the little window when the burner has switched off.

Could it be that as the boiler cools down there is a faulty gasket or something that is allowing air to pass somewhere (releasing a vacuum or something)?

Any ideas would be appreciated. I could phone Scottish Power yet again however I think this issue would be difficult to diagnose because it would be difficult to replicate when the engineer is here.

Best regards,

Rob

HI

is the pump overrun provided ?the pump should stay on for few minutes after the burner has been turned off to take the heat out from boiler.
if this does not happen then pump will stop suddenly when the burner is turned off causing excessive heat to be trapped which causes loud noise.





FED UP OF COWBOYS ?TRY INDIANS

Hi there,

I can hear the pump running for about 8 mins so I don't think it is that. There's usually a click from the boiler PCB (probably a relay or something) and then the pump turns off.

Rob

HI

then i suggest that you check the noise from zone valve/three port valve.