E07 Boiler Fault Code: What It Means on Every Brand

The E07 fault code appears on 2 boiler brands — Biasi and Keston — 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 E07 means	Severity	DIY?
BBiasi	The E07 (also displayed as ER07 on some Biasi models) fault code indicates that the boiler's PCB has detected a problem with the domestic hot water (DHW) NTC temperature sensor — sometimes… Full guide →	Lockout — engineer likely	No
KKeston	The E07 code means your Keston boiler has detected a fan failure — either the fan is not spinning at all, or it is not reaching the speed the boiler expects. Full guide →	Lockout — engineer likely	No

E07 brand by brand

Biasi E07

The E07 (also displayed as ER07 on some Biasi models) fault code indicates that the boiler's PCB has detected a problem with the domestic hot water (DHW) NTC temperature sensor — sometimes referred to as the hot water probe. This sensor continuously feeds temperature readings back to the PCB so the boiler can regulate hot water output safely. When those readings fall outside acceptable limits, or stop arriving altogether, the PCB assumes something is wrong and shuts the boiler down into lockout to prevent potential damage. In practical terms: your boiler will stop working and the E07 or ER07 code will sit on the display until the underlying fault is identified and fixed. On some newer Biasi models this fault may appear as E164 or A07, which carries the same meaning — a DHW temperature sensor fault or excessive hot water temperature.

Causes, fixes & costs for Biasi E07 → · All Biasi codes

Keston E07

The E07 code means your Keston boiler has detected a fan failure — either the fan is not spinning at all, or it is not reaching the speed the boiler expects. Because the fan is responsible for pushing combustion gases safely out through the flue, your boiler's PCB will refuse to attempt ignition without confirmed fan operation. The boiler enters a hard lockout and will not restart automatically; you must press the Reset button once the underlying fault has been addressed. Keston's twin-flue design makes the venturi and air pathways particularly susceptible to blockages from dust and spider webs, so this code appears more frequently on Keston appliances than on single-flue boilers of comparable age.

Causes, fixes & costs for Keston E07 → · All Keston codes

Frequently asked questions

Is the E07 fault code the same on every boiler?

Broadly, yes — on Biasi and Keston the E07 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 E07 fault myself?

Not usually. On every brand listed, E07 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 E07 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.