Vaillant combi boiler aqua plus f37 fault Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[Jeffwhite]

Vaillant combi Aqua Plus (vui 362-7). Fault code f37 appeared ( "rotary speed of the fan is too high or too low - air pressure switch defect, fan defect, electronics defect" according to manual). Plumber has replaced fan and PCB and Air Pressure Switch ( in that order) . Costing a lot up to now. Still f37 appears, particularly when boiler going for more than 2 minutes or so. Easy to reset and restart boiler though. Plumber and I out of options. Also tried repositioning something in the top of the boiler - a restrictor? Boiler is in the loft. Need advice before I start spending more. Don't want to give up yet. Boiler maybe 8 years old.