Display shows F40; unit may not start or may shut down shortly after starting.
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: Gas valve faults can lead to unsafe combustion. Turn off gas and power and do not attempt to adjust or repair the gas valve yourself.
User-level action:
- Reset: After a full power-off period, restore power and attempt a reset. If F40 returns, further use is unsafe.
Professional help: A licensed gas technician must test the gas valve coil resistance, verify correct operation, and replace the gas valve or PCB as needed.