Worcester Bosch Greenstar CDi Classic System ErP fault A7
Hot water NTC sensor defective
Gas boilerWhat it means
The hot water NTC (negative temperature coefficient) sensor has been detected as defective, indicating a circuit break or short circuit in the sensor or its wiring.
Likely causes
- Circuit break in hot water NTC sensor
- Short circuit in hot water NTC sensor
- Faulty connecting lead
Where to start
- Check hot water NTC sensor for circuit breaks/short circuits
- Check connecting lead for circuit breaks/short circuits
The full answer, free
- How to put it right, step by step
- The manual page for this fault (page 52), right under the answer
Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.
From the Worcester Bosch manual for the Greenstar CDi Classic System ErP. Check the model on the data plate before you order parts.