Dunkirk Error A24: Three flame failures
Lockout Alarm: the burner lit but lost flame (flame failure) three times, so the control latches a lockout. The troubleshooting tree checks the flame sensor connection, contamination, and flame signal (should be greater than ~3.7 uA). Display shows 'A24 3 flame failures'. Manual RESET required. We diagnose and repair it across Greater Vancouver — same-day and after-hours.
Lockout Alarm: the burner lit but lost flame (flame failure) three times, so the control latches a lockout. The troubleshooting tree checks the flame sensor connection, contamination, and flame signal (should be greater than ~3.7 uA). Display shows 'A24 3 flame failures'. Manual RESET required.
Dunkirk fault codes can vary by model and series. Use this as a guide — the same code can have more than one cause. Our Technical Safety BC–licensed technicians read the code, confirm it against your unit's manual, and diagnose the true cause before any repair.
Likely causes of Dunkirk error A24
- Dirty, corroded or contaminated flame sensor rod
- Poor/loose flame sensor harness connection
- Weak flame signal (below ~3.7 uA)
- Marginal gas pressure or unstable flame
- Failed flame sensor or burner needing replacement
What you can safely check
- Confirm the gas shutoff valve is fully open
- Press RESET once and watch whether the flame holds
Beyond these checks, do not open the unit or touch gas/electrical parts — BC law requires a licensed gas fitter. Call us for a proper diagnosis.
Error A24 usually leaves you without heat or hot water and can indicate a safety-related fault. Don't keep resetting it — call for priority after-hours Dunkirk repair.
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Parts often behind Dunkirk error A24
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Dunkirk Error A24 Repair Across Metro Vancouver
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