E18
Danfoss
Flue Draft / Wind Pressure Disturbance
Furnace intermittently locks out with E18 during windy conditions, burner stops unexpectedly
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Improper flue terminal location, wind-induced backdraft, weak induced draft fan, incorrectly set Danfoss draft sensor
How to Fix / Troubleshooting
Safety first: Turn off power before accessing the flue or roof. Working at height requires proper safety equipment.
Steps:
- Inspect flue terminal: Check that the flue outlet meets clearance requirements from walls, corners, and roof features. Obstructions can cause turbulence and backdraft.
- Secure flue joints: Ensure all flue sections are properly joined and sealed to prevent air leaks that affect draft sensing.
- Check draft sensor tubing: For systems with a Danfoss draft sensor, inspect the sensing tube for blockages or disconnections.
- Observe operation: During a call for heat, observe the flame through the inspection port. If the flame is being blown off the burner during gusts, consult a technician to evaluate flue design and fan performance.
Advertisements
Repair Difficulty
Hard
4/5
Advertisements