BoilerFaultCodesChaffoteaux 09 Fault Code
The Chaffoteaux 09 fault code means: your boiler has lost the ability to measure the temperature of your hot water, which means it will stop providing hot water until the faulty sensor is replaced.. It appears on 5 Chaffoteaux models in our database.
Technical description: Domestic Hot Water thermistor faulty (open circuit)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like 09: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Chaffoteaux models that show the 09 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Chaffoteaux 09 fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.
- Chaffoteaux Calydra 100 manual (PDF)
- Chaffoteaux Calydra 24 Green manual (PDF)
- Chaffoteaux Talia Green 25 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026