D3 232 — External switching contact opened

What does D3 232 mean?

An external switching contact has opened. This contact could be part of an external control device connected to the boiler, causing it to stop operating.

• Faulty external control device or thermostat.
• Wiring issue with the external switching contact.
• Manual intervention opening the contact.

Click steps to track your progress.

1. 1

   Check any external thermostats or control systems connected to your boiler for errors or manual overrides.

2. 2

   Ensure all visible wiring to external controls is secure and undamaged.

3. 3

   Reset the boiler and the external control device. If the problem persists, contact a heating engineer.