Dunkirk Error b08: Air pressure switch contacts open - soft lockout
Soft (auto-reset) lockout: the 0.14in air pressure switch contacts are open, so the control cannot confirm airflow. The display flashes '9' then 'b' followed by code 08; the boiler restarts automatically once the condition clears (or press RESET). We diagnose and repair it across Greater Vancouver — same-day and after-hours.
Soft (auto-reset) lockout: the 0.14in air pressure switch contacts are open, so the control cannot confirm airflow. The display flashes '9' then 'b' followed by code 08; the boiler restarts automatically once the condition clears (or press RESET).
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 b08
- Moisture/condensate in the pressure switch or tubing
- Blocked or restricted intake/exhaust vent
- Pressure switch out of calibration or failed
- Disconnected or kinked pressure switch hose
- Blower not yet producing required pressure
What you can safely check
- Check the outdoor vent terminals are clear of snow, ice, or debris
- Confirm the boiler relights on its own once any blockage is cleared
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 b08
Genuine Dunkirk parts we supply and professionally install — never for DIY.
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Dunkirk Error b08 Repair Across Metro Vancouver
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