Applicable Systems
Baxi Heating Boiler
Symptoms
The Baxi boiler displays fault code BX001, indicating ignition failure. The boiler has attempted to ignite the burner multiple times without success and has locked out for safety.
Possible Causes
- Gas supply is interrupted or the gas valve is not opening to deliver gas to the burner
- Ignition electrode is fouled with carbon or the spark gap has drifted out of specification
- Flame detection electrode is not sensing the flame signal correctly due to a cracked ceramic or damaged wire
Troubleshooting Steps
- Step 1: Check the gas supply pressure at the boiler gas inlet test point
Gas pressure is at the nominal supply pressure, typically 20 mbar for natural gas in the UK - Step 2: Inspect the ignition electrode for carbon buildup and measure the spark gap
Electrode is clean and the spark gap is 3-4mm as specified in the installation manual - Step 3: Verify the flame detection electrode continuity and the flame signal voltage during ignition
Flame signal is at least 2 microamps DC during the ignition attempt, confirming the flame rectification circuit is functional
How to Reset
To reset: 1) Restore gas supply and check for air in the gas line. 2) Clean or replace the ignition electrode. 3) Press and hold the RESET button for 3 seconds. 4) Verify ignition succeeds and the flame is stable.
Source: Baxi Boiler Manual, Baxi Heating UK Ltd
Category: Home Boiler