Locking fault 1/l/ (2/1/1) - No connection between UBA 3 contacts 78 and 50

What does 1/l/ mean?

There is a connection issue between specific contacts (78 and 50) on the UBA 3 installation base. This prevents the boiler from operating for heating or domestic hot water. As a locking fault, the boiler should attempt to clear itself.

• Loose or faulty connection between UBA 3 contacts
• UBA 3 defect

Click steps to track your progress.

1. 1

   Allow the boiler to attempt an automatic reset.

2. 2

   Power cycle the boiler by switching it OFF and then ON again using the main power switch.

3. 3

   If the fault persists, contact a qualified service technician to inspect the UBA 3 wiring.