What does E66 mean?

The boiler has detected an obstruction in the flue duct when operating at its minimum power setting.

• Partial blockage in the flue duct.
• Issues with flue gas extraction at low fan speeds.

Click steps to track your progress.

1. 1

   Turn off the main power supply to the boiler.

2. 2

   Visually inspect the visible parts of the flue terminal outside for any obvious blockages.

3. 3

   Turn the power back on and see if the error clears.

4. 4

   If the error persists, a qualified technician must inspect the flue duct for obstructions.