S.42 — Accessory module or defective condensate pump blocking burner

What does S.42 mean?

An accessory module or a faulty condensate pump is preventing the boiler's burner from operating. This indicates a problem with an external component connected to the boiler.

• Defective condensate pump.
• Faulty accessory module.
• Blocked condensate drain.

Click steps to track your progress.

1. 1

   Check the condensate drain for any blockages or kinks in the pipework leading away from the boiler.

2. 2

   Ensure any accessory modules are correctly connected and powered.

3. 3

   If the issue persists, contact a qualified service technician to inspect the condensate pump and accessory module.