What does E261 mean?
Burner failed to light within the allowed ignition trial period.
Common causes
- Failed hot surface igniter
- Dirty flame sensor
- Gas supply interruption
- Faulty gas valve
- Incorrect gas pressure
Diagnostic & testing steps
- 1. Test igniter resistance: 40-90 ohms (silicon nitride), 200+ ohms (silicon carbide)
- 2. Clean flame sensor with emery cloth - check for white oxidation
- 3. Verify gas supply is on and pressure is correct
- 4. Test 24VAC to gas valve on W call
- 5. Test gas valve coil resistance: ~30-60 ohms each coil
OEM parts & part numbers
Hot Surface Igniter, Flame Sensor, Gas Valve
Part numbers: 81W43, 21L56, 10L44
Safety warning
⚠️ GAS HAZARD: Ensure ventilation when checking for gas leaks. Do not attempt ignition with suspected gas leak.
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