Boiler shows E09; no response to thermostat demand; control panel may be blank or partially lit
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
Safety first: Isolate power before removing any covers. Electronic boards can carry residual charge.
User checks:
- Power supply: Confirm the fused spur is on and the fuse is intact. Check that other electrical appliances on the same circuit work.
- Visual inspection: If you can safely remove the front cover, look for obvious signs of damage on the Dimplex PCB (burn marks, melted components, water staining). Do not touch the board components.
- Reset: Perform a full power cycle. If E09 reappears immediately, further work should be done by a professional.
Professional repair: A qualified engineer should test supply voltages, low-voltage outputs, and communication lines, and replace the Dimplex main control PCB if confirmed faulty.
Repair Difficulty
Required Part
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