A06
De Dietrich Air Pressure Switch / Fan Proving Fault

Boiler shows A06, fan may run but ignition does not start

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

Faulty air pressure switch, blocked flue or air intake, faulty fan, blocked venturi or pressure tubing

How to Fix / Troubleshooting

Safety: Isolate power and gas before opening the boiler. Flue and combustion checks must be done by a competent person.

  • Check flue terminal: Ensure the flue outlet is not obstructed.
  • Inspect pressure tubes: With power off, remove the boiler front panel and check the silicone tubes between the fan/venturi and the air pressure switch. Look for splits, kinks, or water inside. Replace or dry as needed.
  • Listen to fan: When the boiler starts, listen for the fan. If it does not run or is noisy, the fan assembly may be failing.
  • Technician tasks: A heating engineer should test the air pressure switch contacts, measure fan speed, and verify correct flue installation. Replace the air pressure switch or fan if defective.
Advertisements

Repair Difficulty

Professional Required 5/5

Required Part

Air Pressure Switch
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements