E18
SunHeater
Combustion Blower Speed / Tachometer Fault
Heater shows E18; fan/blower speed seems abnormal or noisy
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
Failed blower motor, Faulty blower speed sensor, Obstructed blower wheel, Control board speed circuit fault
How to Fix / Troubleshooting
Safety: Turn off power and gas. Blower edges can be sharp; wear gloves.
- Inspect blower wheel: Remove the Combustion Blower Assembly cover and check for debris, leaves, or insect nests in the wheel. Clean carefully.
- Check motor bearings: Spin the blower wheel by hand. It should rotate smoothly without grinding. Replace the blower if seized or excessively noisy.
- Verify tachometer wiring: Some blowers have a tachometer feedback wire to the control board. Ensure this connector is secure and not damaged.
- Measure motor current draw: With power restored and the heater calling for heat, measure blower current and compare to the nameplate rating. Overcurrent indicates a failing motor.
- Replace blower or board: If the blower cannot reach the commanded speed or the tach signal is missing, replace the blower. If a new blower still results in E18, the main control board may be at fault.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Combustion Blower Assembly
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements