E07
CTC
Fan Speed / Tachometer Fault
Boiler locks out with E07; fan may start but ignition does not proceed.
Advertisements
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.
Advertisements
Possible Causes
Faulty fan speed sensor, Blocked fan or stiff bearings, Damaged fan wiring, Faulty main PCB fan control
How to Fix / Troubleshooting
Safety: Isolate power. Do not run the boiler with the combustion cover removed.
- Visual inspection: Remove the boiler front panel and inspect the fan assembly. Check for signs of overheating, debris, or water ingress.
- Spin test: Gently rotate the fan impeller by hand (with power off). It should spin freely without grinding. If stiff or seized, replace the fan assembly.
- Check wiring: Ensure the multi-pin connector between the fan and PCB is fully seated and free of corrosion. Inspect the cable for damage.
- Speed feedback (technician): Using the CTC service manual, check the tachometer signal from the fan to the PCB with a multimeter or oscilloscope. If no signal is present while the fan is powered, replace the fan.
- PCB control (technician): If a known-good fan still triggers E07, the PCB may not be driving or reading the fan correctly. Replace the main control PCB as per CTC guidelines.
Advertisements
Repair Difficulty
Hard
4/5
Advertisements