Boiler shows E7 and will not start, fan may not run

Safety first: Disconnect power before accessing the fan assembly. The fan has sharp edges and may start unexpectedly if power is applied.

• Step 1 – Listen for fan operation: On a call for heat, the fan should start before ignition. If there is no sound, suspect a fan or control issue.
• Step 2 – Inspect fan and wiring: Remove the boiler front cover. Locate the combustion blower. Check the wiring harness for secure connections, damage, or signs of overheating. Reseat connectors on both the fan and main PCB.
• Step 3 – Check for obstructions: Spin the fan wheel by hand (with power off). It should rotate freely without scraping. Remove any debris or buildup.
• Step 4 – Electrical tests: Using a multimeter, verify that the fan receives the correct voltage from the main PCB when a call for heat is present. If voltage is present but the fan does not run, replace the fan assembly. If no voltage is present, the main PCB may be faulty.
• Step 5 – Replace fan: If the fan is seized or noisy, replace the combustion blower with the specified Rheem part. Ensure gaskets and seals are correctly installed to prevent flue gas leaks.

Warning: Improper sealing of the combustion chamber or vent connections after fan replacement can lead to flue gas leakage and carbon monoxide hazards. If unsure, use a professional.