E8
Fraser-Johnston
Indoor Overheat / Low Airflow Protection
E8 displayed, unit shuts down due to low indoor airflow or overheat
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Possible Causes
Clogged return air filter, Blocked supply or return ducts, Failed indoor blower motor, Dirty indoor evaporator coil
How to Fix / Troubleshooting
Safety: Turn off power at the breaker before opening the air handler.
- Replace or clean filter: Locate the Fraser‑Johnston air handler filter rack or return grille filter. Replace disposable filters or wash reusable ones. Use the correct size and MERV rating.
- Inspect ducts: Check for closed or blocked supply registers and return grilles. Open all registers and remove obstructions.
- Check blower operation: With panels in place and power restored, set the thermostat fan to ON. If the blower does not run or is weak, inspect the blower motor, capacitor (if PSC), and control board outputs.
- Clean indoor coil: If accessible, inspect the evaporator coil for dust buildup. Clean with a non-acidic coil cleaner and soft brush.
- Reset error: After restoring airflow, power cycle the unit to clear E8 and test operation.
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Repair Difficulty
Easy
2/5
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