414 Boiler Fault Code: What It Means on Every Brand

The 414 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 414 means	Severity	DIY?
AAriston	Fault code 414 (displayed as '4 14' on the boiler's screen) tells you that the boiler's control system has lost communication with the room temperature sensor assigned to Zone 4 of a… Full guide →	Lockout — engineer likely	No
CChaffoteaux	On Chaffoteaux boilers that use a grouped error-code display, this fault is most commonly shown as '4 14' — the first digit indicating the functional group (group 4 relates to external… Full guide →	Engineer may be needed	No

414 brand by brand

Ariston 414

Fault code 414 (displayed as '4 14' on the boiler's screen) tells you that the boiler's control system has lost communication with the room temperature sensor assigned to Zone 4 of a multi-zone heating setup. The boiler expects to receive a signal from that sensor but is getting nothing back — either because the circuit is broken (open circuit), the wiring has shorted, the sensor itself has failed, or Zone 4 has been enabled in the boiler's configuration without a physical sensor actually being connected. This code belongs to a family of zone sensor faults: 411 covers Zone 1, 412 covers Zone 2, 413 covers Zone 3, and 414 covers Zone 4. All four indicate the same underlying type of problem — a room sensor circuit fault — just for different zones. Without a valid reading from the Zone 4 sensor, the boiler cannot correctly control heating in that zone and will lock out or restrict operation until the issue is resolved.

Causes, fixes & costs for Ariston 414 → · All Ariston codes

Chaffoteaux 414

On Chaffoteaux boilers that use a grouped error-code display, this fault is most commonly shown as '4 14' — the first digit indicating the functional group (group 4 relates to external control and peripheral devices), and the second number identifying the specific fault within that group. Code 414 most likely points to a temperature probe fault on an external zone board — for example, a failed or out-of-range NTC thermistor on an auxiliary or zone heating circuit. Codes in the 411–413 range on the same boilers signal temperature probe issues in neighbouring zones, which strongly supports this interpretation for 414. The boiler may lock out or stop heating in the affected zone, and the fault display may alternate between '4' and '14' on models with a two-digit screen. Because Chaffoteaux fault codes vary by model, always cross-check this meaning against the label on the inside of your boiler casing or the installation manual for your specific unit.

Causes, fixes & costs for Chaffoteaux 414 → · All Chaffoteaux codes

Frequently asked questions

Is the 414 fault code the same on every boiler?

No. 414 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 414 fault myself?

Not usually. On every brand listed, 414 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 414 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.