Dunkirk Error E35: False flame detected
Blocking (auto-reset) error: the control detects a flame signal when there should be none ('false flame detect'). The boiler holds off and returns to standby automatically when the condition clears. Display shows 'E35 False flame detect'. The troubleshooting tree checks for an actual flame through the sight glass and may point to a leaking gas valve. We diagnose and repair it across Greater Vancouver — same-day and after-hours.
Blocking (auto-reset) error: the control detects a flame signal when there should be none ('false flame detect'). The boiler holds off and returns to standby automatically when the condition clears. Display shows 'E35 False flame detect'. The troubleshooting tree checks for an actual flame through the sight glass and may point to a leaking gas valve.
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 E35
- Gas valve leaking through (real flame present when it should be off)
- Contaminated or shorted flame sensor giving a false signal
- Moisture/carbon on the flame rod
- Control module fault
What you can safely check
- If you smell gas or see the burner staying lit when it should be off, shut off the gas and call a technician
- Otherwise have a technician inspect the flame sensor and gas valve - no homeowner-safe internal check
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.
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Parts often behind Dunkirk error E35
Genuine Dunkirk parts we supply and professionally install — never for DIY.
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Dunkirk Error E35 Repair Across Metro Vancouver
Frequently Asked Questions
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