Boiler locks out with F.07, fan may run but ignition does not occur
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Critical safety warning: Gas valve diagnostics and replacement must be performed by a licensed gas technician. Do not attempt to disassemble or adjust the gas valve yourself.
- Check gas supply: Verify the manual gas shutoff valve to the boiler is open. Confirm gas service to the building is active.
- Inspect wiring: With power off, inspect the harness from the control board to the gas valve. Ensure connectors are fully seated and wires are not damaged.
- Reset boiler: Restore power and attempt a reset. If F.07 reappears immediately, the control may not be energizing the valve or is detecting a valve fault.
- Do not bypass: Never jumper or bypass the gas valve or safety circuits to force operation.
Professional help: A technician should measure voltage to the gas valve during ignition, check coil resistance, and verify proper gas pressure and combustion. Replacement must use an OEM Lochinvar-specified gas valve.
Repair Difficulty
Required Part
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