Error code
Baxi Boiler Fault Code 125
Water circulation or pump performance issue The most likely cause is pump issue. Check first: do not dismantle pumps, valves, or pipework yourself.
Quick answer
125: Water circulation or pump performance issue
Meaning
Water circulation or pump performance issue
First safe check
Check the boiler pressure and any obvious user controls described in the manual.
Stop if
Stop if the code returns after one safe check or the next step would require internal access.
Who to call
If circulation faults return, book a qualified heating engineer rather than continuing to reset the boiler.
High severity: escalate quickly if it persists. Keep checks outside the casing and use only a manufacturer-approved reset where the manual allows it.
What does this error code mean?
Baxi boiler fault code 125 usually points to poor water circulation through the boiler or heating system, often involving the pump, trapped air, or a blockage.
In practice, 125 is commonly linked to Pump issue, Restricted circulation through the system, or Airlock or sensor reading linked to poor flow.
Start with this safe check: Check the boiler pressure and any obvious user controls described in the manual. If the code returns, the fault worsens, or the appliance does not behave normally, if circulation faults return, book a qualified heating engineer rather than continuing to reset the boiler.
Why is this happening?
- Pump issue
- Restricted circulation through the system
- Airlock or sensor reading linked to poor flow
How to fix this safely
- Check the boiler pressure and any obvious user controls described in the manual.
- Do not dismantle pumps, valves, or pipework yourself.
- Use a standard reset only if the manufacturer guidance allows it.
Reset steps
- Try a single user reset after any permitted checks are completed.
- Arrange an engineer if circulation-related faults return.
When to call a heating professional
If circulation faults return, book a qualified heating engineer rather than continuing to reset the boiler.
Safety warning
Do not open the casing or interfere with pumps, valves, or sealed system components.
Useful hub links
Related circulation fault codes
Relevant guide
Frequently asked questions
Can I keep resetting a Baxi boiler with 125?+
No. If 125 returns after one standard user reset, stop there and arrange a qualified engineer if the manual gives no safe next step.
Is 125 something I can repair myself?+
Boiler faults should be treated cautiously. Stay within the user checks in the manual, and leave gas, combustion, and internal boiler repairs to a qualified professional.