Verified boiler fault code
Potterton E110 Fault Code (Assure Combi & System)
The boiler maximum temperature was exceeded, or the safety thermostat sensor tripped.
Safety disclaimer
Fault code summary
- Manufacturer
- Potterton
- Fault code
- E110
- Fault type
- Overheating, Safety lockout
- Severity
- lockout
- Reset
- Not specified
- Applicable models
- Potterton Assure Combi, Potterton Assure System
Quick answer
The boiler maximum temperature was exceeded, or the safety thermostat sensor tripped.
What does this fault code mean?
The boiler maximum temperature was exceeded, or the safety thermostat sensor tripped.
Common causes
- Maximum temperature exceeded for gradient.
- Safety thermostat sensor tripped.
Symptoms
- The boiler displays E110 and may lock out.
What can the homeowner safely check?
- Note the code and allow the appliance to cool before seeking advice.
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 temperature rise, pump operation, circulation and the safety thermostat.
Applicable boiler models
Related fault codes
- E09 — Assure Combi & System
Gas valve connection fault.
Read fault code - E10 — Assure Combi & System
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Precirculation alarm.
Read fault code - E118 — Assure Combi & System
Water pressure is low, below 0.5 bar.
Read fault code - E12 — Assure Combi & System
Differential water-flow switch fault; the switch is still open.
Read fault code - E125 — Assure Combi & System
Water circulation fault.
Read fault code - E128 — Assure Combi & System
Safety error for frequent loss of flame.
Read fault code - E129 — Assure Combi & System
Safety error for frequent loss of flame with maximum correction during ignition calibration.
Read fault code
Manufacturer documentation
Boiler Error Codes | BaxiPotterton Assure Combi & System — E110: Boiler max. temperature exceeded for gradient; safety thermostat sensor tripped.
Last verified
2026-09-12
Frequently asked questions
What does Potterton E110 mean?
The boiler maximum temperature was exceeded, or the safety thermostat sensor tripped.