E154 — Plausibility test (flow/return) failure

What does E154 mean?

The boiler's system has failed a plausibility test between the flow and return temperatures, suggesting an issue with water circulation or sensor readings.

• Incorrect water circulation.
• Blocked or jammed pump.
• Incorrect positioning of flow/return sensors.
• Faulty sensors.

Click steps to track your progress.

1. 1

   Turn off the main power supply to the boiler, wait 30 seconds, then turn it back on.

2. 2

   Ensure all heating system valves are fully open.

3. 3

   Check the system water pressure on the boiler's gauge and re-pressurize if too low.

4. 4

   If the error persists, a qualified technician should check the water circulation, pump, and sensor positions.