How much does it cost to fix Grant error code U2453?

Typical repair cost for the Grant U2453 fault is £250-550 including labour.

U2453 High

Grant U2453 Fault Code

Q: What does the Grant U2453 fault code mean?

The boiler's internal computer has encountered a communication error between its memory and control systems, which prevents it from running correctly.

The Grant U2453 fault code means: the boiler's internal computer has encountered a communication error between its memory and control systems, which prevents it from running correctly.. It appears on 2 Grant models in our database.

Technical description: Fault U: Network CodeProblem is climate control system, lighting, airbags, etc..fault two; MFG – Manufacturer Specificfault four; Transmissionfault five; TP Sensor Learn Not Completefault three; Transmission Control Module Reprogrammable Memory

What causes the Grant U2453 fault?

This fault occurs when the boiler's internal electronic brain suffers a data failure, meaning the different components can no longer talk to each other reliably. It is usually caused by a physical hardware failure within the circuit board or a corruption of the stored settings that dictate how the boiler should operate. Without this internal communication, the system shuts down as a safety precaution to avoid running blindly.

Typical repair cost £250-550 (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 U2453 fault code

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

Source

Grant U2453 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