12 — Hydraulic differential pressure switch switching failure

What does 12 mean?

The pressure switch in the hydraulic system is not operating correctly, possibly due to a problem with its contacts or the wiring. This is critical for boiler safety and operation.

• Faulty pressure switch operation
• Issues with the wiring to the pressure switch

Click steps to track your progress.

1. 1

   Press and hold down the Reset button for 2 seconds to try clearing the fault.

2. 2

   Check the boiler's pressure gauge to ensure the system pressure is within the normal range (between 0.5 and 1.5 bar when cold).

3. 3

   If the fault persists, contact an Authorised Service Centre for a professional inspection of the pressure switch and wiring.