E02
ACV
Flame Loss During Operation
Boiler locks out with E02, burner stops shortly after ignition or during operation
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Unstable gas supply pressure, Blocked or partially blocked burner, Faulty flame sensor, Faulty gas valve modulation coil
How to Fix / Troubleshooting
Safety first: Switch off power to the boiler and close the gas valve if you smell gas. Do not attempt to adjust gas valves yourself.
- Check other gas appliances: If other gas appliances are also going out or struggling, contact your gas supplier to check supply pressure.
- Reset and observe: Reset the ACV boiler and watch through the inspection window (if present). If the flame lights and then goes out repeatedly, note any unusual noises (popping, roaring) and report them to a technician.
- Ventilation and flue: Ensure the flue terminal is not blocked by debris, snow, or vegetation. Confirm that air intake and ventilation openings around the boiler are clear.
- Professional checks required: A certified technician should clean the ACV burner, check the flame sensor signal, verify gas valve modulation, and perform combustion analysis. Do not attempt burner removal unless trained.
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Repair Difficulty
Hard
4/5
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