Furnace display shows E07, inducer may start but system quickly shuts down before ignition.

Safety first: Turn off power and gas. Do not operate the furnace with suspected combustion air blockage.

• 1. Inspect combustion air intake: Follow the intake PVC pipe from the furnace to the outside. Remove any obstructions such as leaves, snow, or insect nests at the termination hood.
• 2. Check intake connections: Ensure all joints on the Thermia intake piping are properly glued or clamped and not drawing air from inside the furnace room instead of outdoors.
• 3. Examine inducer assembly: Remove the inducer cover (if accessible) and inspect the fan wheel for debris or damage. Make sure it spins freely.
• 4. Test air pressure switch: Similar to the flue pressure switch, check tubing for kinks or water. Test continuity when the inducer runs. Replace the air pressure switch if it does not close under proper draft.
• 5. Reset and test: Restore power and gas, then call for heat. If E07 persists, a technician should measure combustion air flow and verify correct venting per Thermia installation guidelines.