Boiler display shows E03; fan or air proving fault similar to A03 on some models.

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.

Possible Causes

Blocked vent or intake, Failed air pressure switch, Faulty fan motor, Disconnected pressure tubing

How to Fix / Troubleshooting

Follow the same safety and diagnostic steps as for an A03 air pressure fault: inspect venting and intake, verify pressure tubing integrity, and confirm blower operation. Do not operate the boiler until any vent blockage is cleared.

Repair Difficulty

Medium 3/5

Required Part

Air Pressure Switch

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