LED 1 Slow Flashing (2Hz) High

Halstead LED 1 Slow Flashing (2Hz) Fault Code

Also written as LED1SLOWFLASHING2HZ — same fault.

The Halstead LED 1 Slow Flashing (2Hz) fault code means: your boiler's internal computer is experiencing a critical error and cannot safely operate the system.. It appears on 1 Halstead model in our database.

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.

Technical description: PCB Failure
Typical repair cost £250-450 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Halstead models that show the LED 1 Slow Flashing (2Hz) fault code

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

Source

Halstead LED 1 Slow Flashing (2Hz) fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026