How much does it cost to fix Alpha error code 74?

Typical repair cost for the Alpha 74 fault is £150-250 including labour.

74 High

Alpha 74 Fault Code

Q: What does the Alpha 74 fault code mean?

Your boiler has detected a communication error with its internal temperature monitoring system and has automatically shut down to ensure your safety.

The Alpha 74 fault code means: your boiler has detected a communication error with its internal temperature monitoring system and has automatically shut down to ensure your safety.. It appears on 10 Alpha models in our database.

Technical description: Safety flow sensor anomaly. The PCB detects an anomaly on the safety NTC sensor

Typical repair cost £150-250 (including labour)

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 →

Alpha models that show the 74 fault code

Click a model for the full fault code list and model-specific repair notes.

C25 Xtraflame Repair: £150-250
E-Tec Plus Repair: £150-250
E-Tec Plus 24 Repair: £150-250
E-Tec Plus 28 Repair: £150-250
E-Tec Plus 33 Repair: £150-250
H25 Xtraflame Repair: £150-250
Intec 28GS Repair: £150-250
Intec 50CS Repair: £150-250
Intec2 25 28XE Repair: £150-250
Intec2 30SE Repair: £150-250

Source

Alpha 74 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026