CH PUMP indicator Fast flash High

Grant CH PUMP indicator Fast flash Fault Code

Also written as CHPUMPINDICATORFASTFLASH — same fault.

The Grant CH PUMP indicator Fast flash fault code means: your boiler is struggling to accurately read the temperature of the water flowing into your radiators, which prevents it from heating your home correctly.. It appears on 6 Grant models 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: Fast flash (twice per second): Indicates a possible fault with the ‘Flow’ thermistor. Check CH ‘Flow‘ thermistor connection to PCB. Replace ‘Flow’ thermistor.
Typical repair cost £120-200 (including labour)

Engineer required

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

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Grant models that show the CH PUMP indicator Fast flash fault code

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

Source

Grant CH PUMP indicator Fast flash fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.

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