Control board shows E6; blower runs but no heat

Safety: Disconnect power before accessing wiring or switches.

• 1. Check air filter and vents: Replace dirty filters and ensure all supply and return vents are open to prevent overheating.
• 2. Inspect wiring harness: Remove the blower door and locate the safety circuit wiring (limit switches, rollout switches). Look for loose spade connectors, burnt wires, or broken insulation. Reseat any loose connectors.
• 3. Locate auxiliary limits: On some Frigidaire furnaces, additional limit switches are mounted on the blower housing or near the heat exchanger. Verify they are securely mounted and wiring is intact.
• 4. Manual reset limits: If any auxiliary limit has a reset button, press it once to reset. If it immediately trips again, stop and call a technician.
• 5. Professional testing: If E6 persists, a technician should ohm-test each limit switch and verify temperature rise and duct static pressure to correct the root cause.