Verified boiler fault code
Main Heating E125 Fault Code (Eco Elite System)
Circulation fault in the primary circuit.
Safety disclaimer
Fault code summary
- Manufacturer
- Main Heating
- Fault code
- E125
- Fault type
- Circulation, Pump
- Severity
- Not specified
- Reset
- Not specified
- Applicable models
- Main Eco Elite 24 System ErP, Main Eco Elite 28 System ErP
Quick answer
Circulation fault in the primary circuit.
What does this fault code mean?
Circulation fault in the primary circuit.
Common causes
- Poor primary circulation.
- The manual associates the code with insufficient temperature change after burner lighting or excessive temperature rise.
Symptoms
- The facia displays E125 and heating may stop.
What can the homeowner safely check?
- Record the displayed code and check only the visible pressure indication.
Boiler reset information
Reset information was not provided in the verified manufacturer source. Do not repeatedly reset an unresolved fault.
When should I call an engineer?
Contact a suitably qualified heating engineer when the fault persists, the boiler locks out, or the manufacturer instructions do not resolve it. For gas appliance work in the UK, use a Gas Safe registered engineer.
Engineer diagnosis
- Investigate primary circulation, pump operation and restrictions.
Applicable boiler models
Related fault codes
- E110 — Eco Elite System
Safety thermostat operated.
Read fault code - E119 — Eco Elite System
Water-pressure switch not operated; the manual states this is shown below 0.5 bar primary-water pressure.
Read fault code - E131 — Eco Elite System
Interruption of power supply while in fault mode.
Read fault code - E133 — Eco Elite System
Interruption of gas supply or flame failure.
Read fault code - E160 — Eco Elite System
Fan or fan-wiring fault.
Read fault code - E20 — Eco Elite System
Central-heating NTC fault.
Read fault code - E28 — Eco Elite System
Incorrect PCB fitted.
Read fault code - E50 — Eco Elite System
Hot-water NTC fault.
Read fault code
Manufacturer documentation
Main Eco Elite System Installation & Service ManualE125 is displayed when boiler temperature has not changed as specified or exceeds the selected temperature; poor primary circulation is indicated.
Last verified
2026-09-12
Frequently asked questions
What does Main Heating E125 mean?
Circulation fault in the primary circuit.