Hi,
10-12 year old Main 12 HE (similar/same to Baxi & Potterton) boiler feeding CH and indirect cylinder. Last night, gone midnight, prep for bed and realised no hot water. Checked the boiler - and this indicates via three front-panel LEDs (On/Off/Off) a "Air Proving LOCKOUT", see https://www.freeboilermanuals.com/assets/pdf/main/Main_HE_Installation_Instructions.pdf (page 34, 39), which I could not manually reset (knob CCW, then CW). Immersion heater on, went to bed.
So, next morning, I removed power from the boiler for 20+ minutes (okay, duration of a bath), then re-applied and watched the behaviour. Upon application of power the Air Proving LED illuminates about 1 second after power, with no sound or indication of any fan, ignitor, etc, occurring. Looking at the diagnostic flowchart there's no clear way for this error to be detected and displayed so soon after power is applied.
Being married, I'm under the cosh to get this fixed, so I've quickly ordered a replacement PCB on the logic that the flowchart doesn't give me a route for this error to occur at least before the boiler fires up. I'm started life as a spark many years ago (okay, aircraft spark), so not afraid of playing with wires, so this looks to be a sensible approach to take for now - but the replacement PCB is scheduled for delivery Fri/Sat (today is Mon).
Rather than wait until then, and then find there's something else wrong, has anyone any insight into the nature of this fault and whether this could likely be a PCB or another more insidious (and expensive) fault that I can start looking at.
Any advice gratefully received.
For now... immersion and fan heaters ftw!
10-12 year old Main 12 HE (similar/same to Baxi & Potterton) boiler feeding CH and indirect cylinder. Last night, gone midnight, prep for bed and realised no hot water. Checked the boiler - and this indicates via three front-panel LEDs (On/Off/Off) a "Air Proving LOCKOUT", see https://www.freeboilermanuals.com/assets/pdf/main/Main_HE_Installation_Instructions.pdf (page 34, 39), which I could not manually reset (knob CCW, then CW). Immersion heater on, went to bed.
So, next morning, I removed power from the boiler for 20+ minutes (okay, duration of a bath), then re-applied and watched the behaviour. Upon application of power the Air Proving LED illuminates about 1 second after power, with no sound or indication of any fan, ignitor, etc, occurring. Looking at the diagnostic flowchart there's no clear way for this error to be detected and displayed so soon after power is applied.
Being married, I'm under the cosh to get this fixed, so I've quickly ordered a replacement PCB on the logic that the flowchart doesn't give me a route for this error to occur at least before the boiler fires up. I'm started life as a spark many years ago (okay, aircraft spark), so not afraid of playing with wires, so this looks to be a sensible approach to take for now - but the replacement PCB is scheduled for delivery Fri/Sat (today is Mon).
Rather than wait until then, and then find there's something else wrong, has anyone any insight into the nature of this fault and whether this could likely be a PCB or another more insidious (and expensive) fault that I can start looking at.
Any advice gratefully received.
For now... immersion and fan heaters ftw!
