How to Fix Baxi E125 Fault Code (UK)
Baxi showing E125 — Circulation fault. UK diagnosis, likely spare (pump / diverter) and step-by-step reset.
Baxi
What the code means
E125 on a Baxi indicates circulation fault. The boiler locks out to protect the heat exchanger and, on gas faults, to comply with the Gas Safety (Installation and Use) Regulations. Always reset to confirm the code is live, not historical.
Likely spare
The most common fix is the pump / diverter. Check the exploded diagram against the GC number on the data plate before ordering — Baxi revised parts on Baxi units mid-production.
Fix procedure
Verify pump on, diverter moves, filters clean.
Log the fault and reset. If the code returns within 24 hours, escalate to full electrical diagnosis with a manometer and multimeter.
Frequently asked questions
- Can I reset E125 myself?
- You can press the reset button up to 3 times. If E125 returns, the boiler needs a Gas Safe engineer — it is illegal to repair gas components without registration.
- Is the part covered under warranty?
- Baxi standard warranty is 2–10 years depending on model. Registered installations get the full term. Check the sticker inside the case.
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