E2
Worcester Bosch
Flow Temperature Sensor (NTC) Fault
Boiler displays E2 and shuts down, often with no heating or hot water.
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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
Open-circuit or shorted flow NTC sensor, Loose NTC wiring connection, Limescale build-up around sensor pocket, Faulty PCB reading sensor incorrectly
How to Fix / Troubleshooting
Safety first: Isolate power and allow the boiler to cool before touching pipework or sensors.
- Reset and observe: Reset the boiler once. If E2 reappears quickly, the sensor or wiring is likely faulty.
- Check connections: Remove the front cover (if user-removable on your model) and visually inspect the flow NTC plug and wiring for damage or disconnection.
- Engineer checks: A technician should measure the resistance of the flow NTC at a known temperature and compare it with Worcester Bosch specifications, inspect for limescale or sludge around the sensor pocket, and replace the NTC or PCB as required.
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Repair Difficulty
Medium
3/5
Required Part
Flow NTC Temperature Sensor
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