Low
T3 on Worcester Bosch Heatslave

Your boiler is performing a routine check of its internal pump and has paused its normal operation to ensure everything is working correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Pump test – checking the basic pump

DIY fix possible

Wait for the test to complete automatically (usually takes a few minutes)Ensure the system pressure is between 1 and 1.5 bar on the pressure gaugeCheck that any isolation valves under the boiler are fully open

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