High
Overheat detection on Chaffoteaux 80/100

Your boiler has shut itself down because it detected that it is running too hot, indicating a potential circulation or sensor problem.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

If an overheat is detected by the sensor (13), the grey security solenoid (30) and the blue 1/3 (31) closes, the orange indicator lamp (21) extinguishes. The ignitor is energised for 8 seconds and the red lockout indicator (22) lights.

From this model's manual
Verified against the Chaffoteaux/Chaffoteaux 80 100 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like Overheat detection: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

All 6 fault codes on the 80/100

Seeing a different code? Every code this model can display, in one place.

LockoutOrange LEDRed indicatorRed LEDRed lockout indicator

Related guides you might find useful

Banging, kettling or whistling noise

Each noise points to a different fault.

Read →

Radiator not heating up

One cold radiator is usually a stuck valve pin or trapped air.

Read →

Hot water works but heating does not

On a combi it is usually the diverter valve. On a system boiler, the motorised valve.

Read →