Heating failures require rapid, accurate diagnosis: gas supply interruptions, contaminated ionization probes, or flue gas pressure switch lockouts. Access our technical guides to diagnose and safely reset your heating equipment.
We couldn't find documented codes for the selected brand in Gas & Oil Boilers.
Applies to: Saunier Duval ThemaPlus / ThemaClassic / IsoMax
Burner ignition failure or loss of flame ionization signal during startup. The boiler enters safety lockout to prevent unburned gas accumulation.
Applies to: Elm Leblanc Acleis / Megalis Condens
Flame not detected during burner operation or lack of ionization current following the ignition sequence.
Applies to: Chaffoteaux Mira C / Urbia / Talia Green
Absence of flame detected. Boiler locks out after 3 consecutive failed ignition attempts to prevent gas buildup.
Applies to: Vaillant ecoTEC plus / ecoTEC pro
Boiler dry-fire protection safety trip. Water pressure in the central heating circuit has fallen below 0.6 bar, disabling burner operation to prevent heat exchanger damage.
Applies to: Worcester Bosch Greenstar i / CDi Classic
Flame sensing failure. The control board attempted 4 ignition trials without sensing a stable flame ionization microamp signal, initiating safety lockout.
Applies to: Baxi 600 / 800 / Duo-tec Combi
The hydraulic pressure sensor microswitch contacts have opened due to central heating system pressure dropping below 0.5 bar.
Prior to performing any diagnostic testing or taking electrical measurements on residential or commercial equipment, always lock out / tag out (LOTO) power sources and shut off fuel or water supplies. Wear rated personal protective equipment (insulated gloves, eye protection) and use a calibrated CAT III/CAT IV digital multimeter.
If fault symptoms persist after executing our pinout checks and component resistance tests, consult a factory-certified technician or licensed HVAC/appliance specialist.