A07 Boiler Fault Code: What It Means on Every Brand

The A07 fault code appears on 2 boiler brands — Ferroli and Vokera — 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 A07 means	Severity	DIY?
FFerroli	The A07 code appears when the flue gas probe detects an excessively high temperature — typically sustained for more than around two minutes — and the boiler shuts itself down as a safety… Full guide →	Lockout — engineer likely	Some checks
VVokera	The A07 code appears on Vokera boilers when the control board detects an abnormal reading from the primary flow thermistor — the temperature sensor mounted on the hot-water outlet side of… Full guide →	Lockout — engineer likely	No

A07 brand by brand

Ferroli A07

The A07 code appears when the flue gas probe detects an excessively high temperature — typically sustained for more than around two minutes — and the boiler shuts itself down as a safety precaution. Because it begins with 'A', this is a lockout fault on Ferroli boilers, meaning the boiler will not restart on its own and needs a manual reset once the underlying problem has been addressed. You may also encounter the related codes F07 and F14 on some Ferroli models: F-prefix codes are 'blocking' faults that can clear automatically when the triggering condition resolves, whereas A07 always requires deliberate intervention. In all cases the root concern is the same — the flue gas pathway or the heat exchanger is running hotter than it should be, and the boiler is protecting itself from damage or a potentially unsafe condition.

Causes, fixes & costs for Ferroli A07 → · All Ferroli codes

Vokera A07

The A07 code appears on Vokera boilers when the control board detects an abnormal reading from the primary flow thermistor — the temperature sensor mounted on the hot-water outlet side of the boiler. NTC thermistors work by changing their electrical resistance as temperature rises or falls; the PCB reads this resistance to judge whether the heating water is at the right temperature. When that signal looks wrong — either because the sensor itself has failed, the water is genuinely overheating, or the board is misreading the data — the boiler locks out and displays A07. This code relates specifically to the central heating flow circuit, not to the domestic hot water sensor.

Causes, fixes & costs for Vokera A07 → · All Vokera codes

Frequently asked questions

Is the A07 fault code the same on every boiler?

Broadly, yes — on Ferroli and Vokera the A07 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 A07 fault myself?

On some brands there are safe homeowner checks first — typically system pressure, the condensate pipe in cold weather, and a single reset. The underlying repair usually needs a registered engineer. Never open the boiler casing yourself.

Who should I call about a A07 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.