Baxi E110: the overheat lockout that is really a circulation message
What Does Error E110 Mean?
Baxi uses E110 for an overheat condition, where the boiler has exceeded its permitted maximum temperature or the safety thermostat has tripped. The measurement is genuine, but heat only accumulates when something stops carrying it away, so the investigation belongs to the water side of the system more often than to the burner. Applies to: Baxi domestic gas boilers using the E-series fault codes listed in Baxi support material Baxi publishes E-series codes across several domestic ranges, and the detail behind a number can differ between them. The list on the label behind the casing flap of your own appliance governs, and a Potterton or Main boiler from the same group carries its own published list even where components are shared. Owner-safe checks: Check the system pressure gauge on the boiler and write down the reading while the system is cold. | Feel every radiator after a heating attempt and record which warm up, which stay cold, and where on the panel the cold begins. | Note any noise from the boiler and whether it coincides with firing, and stop using the heating if kettling is present. Qualified technician: Pump testing and replacement, venting a sealed primary circuit, cleaning or flushing a system, and resetting a tripped safety thermostat are Gas Safe registered tasks. | A boiler that boils audibly should not be run while waiting for an appointment, because each episode damages the heat exchanger surface further.
Diagnostic Tree & Resolution Protocol
Official manufacturer root cause analysis and step-by-step diagnostic workflow.