Baxi Eco Compact Fault codes & diagnostics

3 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Combi Natural Gas 24-30 kW 2018 onwards
GC Numbers 47-467-1447-467-15
Download the Baxi Eco Compact manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number Appliance (register name) Produced
47-467-14 ECO COMPACT 25 COMBI 2018–present
47-467-15 ECO COMPACT 30 COMBI 2018–present
Just want the most common Baxi Eco Compact faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 3 documented codes

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125

Your boiler has detected that the water inside the system isn't circulating or heating up correctly, preventing it from operating safely.

High Engineer only £150-350

Parts commonly replaced

  • Pump
  • Diverter valve
  • NTC thermistor sensor
  • Primary heat exchanger

Related codes

Full explanation for 125
135

Your boiler has stopped working because it cannot light the internal flame or maintain it, likely due to a gas supply issue.

High Engineer only £120-250

Parts commonly replaced

  • Ignition electrode
  • Gas valve
  • PCB

Related codes

Full explanation for 135
E4

Your boiler is having trouble moving water around the system properly before it fires up, often caused by trapped air or low pressure.

High DIY-safe £100-280

What to check first

  1. Check the pressure gauge and top it up to 1.5 bar if it is too low
  2. Ensure all radiator valves and isolation valves under the boiler are fully open
  3. Gently bleed your radiators to remove any trapped air from the system
  4. Reset the boiler by turning the selector switch to 'R' for five seconds

Parts commonly replaced

  • Circulating pump
  • Flow temperature sensor
  • Automatic air vent

Related codes

Full explanation for E4
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