How much does it cost to fix Grant error code CH PUMP indicator Fast flash?

Typical repair cost for the Grant CH PUMP indicator Fast flash fault is £120-200 including labour.

CH PUMP indicator Fast flash High

Grant CH PUMP indicator Fast flash Fault Code

Q: What does the Grant CH PUMP indicator Fast flash fault code mean?

Your boiler's temperature sensor is failing to communicate properly, which is preventing it from heating your water correctly.

Also written as CHPUMPINDICATORFASTFLASH — same fault.

The Grant CH PUMP indicator Fast flash fault code means: your boiler's temperature sensor is failing to communicate properly, which is preventing it from heating your water correctly.. It appears on 5 Grant models in our database.

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 27 April 2026