A7
Worcester Bosch Flow Temperature Sensor / Control Sensor Fault

Boiler displays A7, hot water temperature may be incorrect or boiler may not respond to demand correctly.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Faulty flow NTC sensor, Loose sensor connection, Sensor not correctly clipped to pipe

How to Fix / Troubleshooting

Safety first: Isolate power before removing the boiler case.

Engineer steps:

  • Identify the flow NTC sensor used for control on the flow pipe.
  • Check that the sensor is firmly attached and has good thermal contact with the pipe (use thermal paste or correct clip if specified).
  • Measure resistance and compare with Worcester Bosch NTC tables.
  • Replace the sensor if readings are out of range or intermittent.
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Repair Difficulty

Medium 3/5

Required Part

Flow Temperature Sensor (NTC)
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