Conditions: nearly 10 year old boiler WB2B, heating mode off, DHW on or also in standby, Boiler shows no fault LED on, no new fault logged, room thermostat deactivated.
Boiler gets odd attacks of suddenly turning on the fan 100%, then (gas valve and ignition are clicking?) potentially tries to ignite but doesn't seem to succeed. No flame icon appears.
After 15 s to about 30 s all stops again. It may be quiet for up to 30 minutes and then it tries again. Had it happen three times in very short succession today.
This is in DHW mode or even in Standby, which is most odd.
Other symptoms can be (potentially when the fault develops) that the hot water may abruptly stop and will then not come back on. (Fun when showering.) All sensors measure OK, as expected. Flow switch OK. Thermal protection switch OK. No visible faults, leaks, water pressure good, burner looks fine and was just cleaned, seals OK, electrodes adjusted.
It normally comes to its senses again when it is turned off from mains for a while and is then switched on again. It may then run normally for a day and then the symptoms start again. Burner will then ignite normally and hold the flame when all is good, fan also spins down to heat up the boiler water.
Something triggers the fan and I can't think of what it might be and why it would happen in standby as well. Normally it was always quiet in standby.
Any ideas appreciated!
Mike
Boiler gets odd attacks of suddenly turning on the fan 100%, then (gas valve and ignition are clicking?) potentially tries to ignite but doesn't seem to succeed. No flame icon appears.
After 15 s to about 30 s all stops again. It may be quiet for up to 30 minutes and then it tries again. Had it happen three times in very short succession today.
This is in DHW mode or even in Standby, which is most odd.
Other symptoms can be (potentially when the fault develops) that the hot water may abruptly stop and will then not come back on. (Fun when showering.) All sensors measure OK, as expected. Flow switch OK. Thermal protection switch OK. No visible faults, leaks, water pressure good, burner looks fine and was just cleaned, seals OK, electrodes adjusted.
It normally comes to its senses again when it is turned off from mains for a while and is then switched on again. It may then run normally for a day and then the symptoms start again. Burner will then ignite normally and hold the flame when all is good, fan also spins down to heat up the boiler water.
Something triggers the fan and I can't think of what it might be and why it would happen in standby as well. Normally it was always quiet in standby.
Any ideas appreciated!
Mike
