HVACopediaHTP · Boiler troubleshooting
Lockout on ignition (F09, no flame)
What is going on
Boiler tries to light four times on one call and locks out.
Likely causes
- Spark electrode gap wrong or corroded
- No gas / low gas pressure / air in line
- Dirty flame rectifier
- Blocked flue or condensate
Check in this order
- Watch the igniter through the sight glass
- Set electrode gap to 0.196 in. (5 mm +/-1) and clean corrosion
- Measure gas inlet pressure; 3.5 to 14 in. w.c. with no more than 1 in. drop on light-off
- New or empty LP installs make sure the line was purged
- Check the flame rectifier
- Check flue and condensate for blockage
Applies to: EL-80, EL-110, EL-150, EL-220, EL-299, EL-399 (N/LP)
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Source: Elite EL-80 N Installation Manual (LP-293), p. 71, p. 38. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.