E92 Boiler Fault Code: What It Means on Every Brand

The E92 fault code appears on 2 boiler brands — Baxi and Potterton — and on all of them it points to the same kind of problem. The details still differ by brand (thresholds, sub-codes, reset procedure), so use the table below to jump to the page for your boiler.

Lockout — engineer likely 2 brands use this code

Which brand is your boiler?

The brand is printed on the front casing. Tap your brand for the full causes, fixes and repair costs.

Brand	What E92 means	Severity	DIY?
BBaxi	The E92 code appears on Baxi boilers when a combustion alarm is triggered during the boiler's automatic self-calibration routine. Full guide →	Lockout — engineer likely	No
PPotterton	The E92 code appears when a Potterton boiler runs its automatic combustion self-calibration routine and the results fall outside acceptable limits. Full guide →	Lockout — engineer likely	No

E92 brand by brand

Baxi E92

The E92 code appears on Baxi boilers when a combustion alarm is triggered during the boiler's automatic self-calibration routine. During this auto-setting process, the boiler monitors and adjusts its gas-to-air mixture to ensure safe, efficient combustion. If the readings fall outside acceptable limits at any point during that routine, the boiler locks out and displays E92 as a safety precaution. In plain terms, the boiler has tried to set itself up correctly, found that combustion is not performing as expected, and shut down to protect you. This fault is closely related to the Baxi E55 code, which can appear when calibration is first required — E92 is the alarm raised when that calibration cycle actually fails.

Causes, fixes & costs for Baxi E92 → · All Baxi codes

Potterton E92

The E92 code appears when a Potterton boiler runs its automatic combustion self-calibration routine and the results fall outside acceptable limits. In plain terms, the boiler has tested its own combustion performance, decided something is not right, and shut itself down as a precaution. This is a lockout fault — the boiler will not restart until the root cause has been properly diagnosed and corrected. Because this code relates directly to combustion quality and involves gas-carrying components, it must be investigated by a Gas Safe registered engineer. The E92 is most commonly seen on the Potterton Promax range, though it can appear on other Potterton models that include an auto-calibration function.

Causes, fixes & costs for Potterton E92 → · All Potterton codes

Frequently asked questions

Is the E92 fault code the same on every boiler?

Broadly, yes — on Baxi and Potterton the E92 code points to the same class of fault, and the recommended response is similar. Model-specific details such as sub-codes and reset procedures still vary, so follow the page for your own brand.

Can I fix a E92 fault myself?

Not usually. On every brand listed, E92 points to a fault that needs a suitably registered engineer to diagnose and repair. A single reset to rule out a transient glitch is reasonable; repeated resets are not.

Who should I call about a E92 fault?

For gas boilers, a Gas Safe registered engineer — it is a legal requirement for any work on the appliance. If you smell gas at any point, leave the property and call the National Gas Emergency line on 0800 111 999.

General guidance only — not a substitute for professional advice, and not certified by a registered engineer. Any work on a gas appliance must be carried out by a Gas Safe registered engineer. If you smell gas, call 0800 111 999.