How to Fix / Troubleshooting

Safety first: Turn OFF power at the indoor unit disconnect and breaker before working on the blower.

Step 1 – Replace or clean filter: Remove the return air filter and replace with a clean filter of the correct size and MERV rating recommended by Day & Night. A severely clogged filter can overheat the motor.
Step 2 – Check airflow: Ensure all supply registers and return grilles are open and not blocked by furniture or rugs.
Step 3 – Inspect blower wheel: Remove the blower access panel. Check that the blower wheel spins freely by hand and is not packed with dust or debris. Clean carefully if dirty.
Step 4 – Motor condition: Look for signs of overheating (burnt smell, discoloration) on the blower motor. If the motor is very hot to the touch or noisy, it may be failing and should be replaced.
Step 5 – ECM diagnostics: On ECM motors, check the low-voltage harness to the motor module. Loose connections can cause overcurrent trips.

E8 displayed, unit shuts down after running, may restart after a while

Possible Causes