207 Boiler Fault Code: What It Means on Every Brand

The 207 fault code appears on 2 brands — Ariston and Chaffoteaux — and it does not mean the same thing on each. The same two or three characters can signal a pressure problem on one boiler and an ignition fault on another, so identify your brand first and use the table below to jump to the right page.

Up to: Lockout — engineer likely 2 brands use this code Meaning differs by brand

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 207 means	Severity	DIY?
AAriston	Fault code 207 on an Ariston boiler indicates that the solar collector pipework has reached an excessively high temperature. Full guide →	Engineer may be needed	No
CChaffoteaux	Fault code 207 on a Chaffoteaux boiler sits within the 200-series block, which the boiler's control system reserves exclusively for issues with the domestic hot water (DHW) circuit. Full guide →	Lockout — engineer likely	No

207 brand by brand

Ariston 207

Fault code 207 on an Ariston boiler indicates that the solar collector pipework has reached an excessively high temperature. The boiler's control system monitors the temperature within the solar circuit and triggers this code as a protective measure when it detects overheating in the collector loop. This is a solar-specific fault — it does not indicate a problem with the gas-fired heating circuit itself. In most cases the boiler will attempt to self-protect automatically, but if the underlying cause is not resolved the fault will persist or return. Note: if you see fault code 208 appearing alongside or alternating with 207, this points to a broader solar circuit issue — code 208 indicates low temperature in the collector pipeline, which can suggest a solar pump failure or a loss of fluid in the circuit.

Causes, fixes & costs for Ariston 207 → · All Ariston codes

Chaffoteaux 207

Fault code 207 on a Chaffoteaux boiler sits within the 200-series block, which the boiler's control system reserves exclusively for issues with the domestic hot water (DHW) circuit. Code 207 specifically tells you that the boiler has detected a problem with the NTC thermistor responsible for monitoring your hot water temperature — either the sensor is sending a signal that falls outside the expected range, has developed an open or short circuit, or has lost reliable communication with the main control board. Without a trustworthy temperature reading from this sensor, the boiler cannot safely manage DHW delivery and will lock out to protect itself. On a small number of specialist models with solar integration (such as the Flexiflame 120 NL), 207 can instead flag solar manifold overheating, but on standard combi and system boilers the DHW sensor fault interpretation applies. The 201–209 range appears consistently across the Chaffoteaux Mira, Urbia, Serelia, Niagara C, Talia, and Inoa ranges, so if your display shows 207 you are in the right place regardless of which of these models you own.

Causes, fixes & costs for Chaffoteaux 207 → · All Chaffoteaux codes

Frequently asked questions

Is the 207 fault code the same on every boiler?

No. 207 means different things on different brands — see the table above. Always identify your boiler's brand (it is printed on the front casing) before acting on any advice about the code.

Can I fix a 207 fault myself?

Not usually. On every brand listed, 207 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 207 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.