What does 237 mean?

An external switching contact, such as for a thermostat or safety device, is detected as open. This can prevent the boiler from operating.

• External switching contact is open or malfunctioning
• Incorrect jumper setting on the external switching contact connection

Click steps to track your progress.

1. 1

   Check the external switching contact for proper function and closure.

2. 2

   Verify the jumper setting on the connection of the external switching contact.

3. 3

   If the contact is faulty, it may need to be repaired or replaced.