20 — Short circuit on system flow temperature sensor (low-loss header)

What does 20 mean?

The boiler is regulating without a supply temperature sensor for the low-loss header due to a short circuit in the sensor.

• Short circuit in the system flow temperature sensor
• Damaged wiring to the low-loss header sensor

Click steps to track your progress.

1. 1

   Visually inspect the low-loss header sensor for any visible damage or corrosion.

2. 2

   Check the connecting cables for the low-loss header sensor for any signs of fraying or shorting.

3. 3

   Contact a qualified heating technician to test or replace the low-loss header sensor.