BoilerFaultCodesSime AL 14 Fault Code
Also written as AL14 — same fault.
The Sime AL 14 fault code means: your boiler has detected an issue with the sensor that monitors the heat of the gases leaving your system, which prevents the boiler from running to keep it safe.. It appears on 19 Sime models in our database.
Technical description: EXHAUST TEMPERATURE SENSOR ERROR
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 AL 14: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Sime models that show the AL 14 fault code
Click a model for the full fault code list and model-specific repair notes.
- Brava DGT HE Repair: £120-190
- Brava One HE Repair: £120-190
- Brava Slim HE Regular Repair: £120-210
- Brava Slim HE System Repair: £120-190
- Dewy 30/130 HE FS Repair: £120-£220
- Dewy 30/50 HE WM Repair: £120-£210
- Format DGT HE Combi Repair: £120-£200
- Format DGT HE System Repair: £120-190
- Giulia Combi 30 Repair: £120-220
- Halstead Trio Repair: £120-£210
- iQE Comfort 30 Repair: £120-200
- Meridian HE Repair: £120-220
- Mia 30 Repair: £90-180
- Murelle One HE Repair: £120-220
- Murelle Pro HE 25 HO Repair: £120-£200
- Murelle Pro HE Combi Repair: £120-190
- Murelle Pro HE MkII Combi Repair: £120-220
- Murelle Pro HE R MkII System Repair: £120-£210
- Murelle Pro HE System R Repair: £120-190
Source
Sime AL 14 fault code information on this page is sourced and cross-checked against the official Sime service / installation manuals for each affected model.
- Sime Brava DGT HE manual (PDF)
- Sime Brava One HE manual (PDF)
- Sime Brava Slim HE System manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026