Glow-worm Energy Combi fault F.23
Safety shutdown: temperature spread too great (NTC1/NTC2)
Gas boilerWhat it means
Safety shutdown due to excessive temperature difference between flow and return NTC sensors
Likely causes
- Pump blocked
- Insufficient pump output
- Air in product
- Flow and return NTC sensors connected the wrong way round
Where to start
- Flush the heating installation through
- Check the silicone hose connection (1) between the pump's automatic air vent and the hydraulic console
- Fill with water until the required filling pressure is reached
The full answer, free
- 3 more checks in order
- The readings and component tests from the manual
- 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 Glow-worm manual for the Energy Combi. Check the model on the data plate before you order parts.
Other Glow-worm Energy Combi fault codes
- D.14Operating mode of the modulating pump
- F.00Flow temperature sensor fault
- F.01Return temperature sensor fault
- F.10Short circuit: flow temperature sensor
- F.11Short circuit: return temperature sensor
- F.22Safety shutdown: water deficiency in the boiler
- F.24Safety shutdown: temperature rise too fast
- F.25Safety shutdown: flue gas temperature too high
- F.49EBUS fault: voltage too low
- F.61Fault: gas valve assembly control
- F.62Fault: gas valve switch-off control
- F.70Invalid product code (DSN)
- F.77Fault: condensate or smoke
- P.05Filling the product
- P.06Purging the heating circuit
- S.42Flue non-return flap closed
- S.53Product in waiting period / operating block due to water deficiency (flow/return...
- S.54Waiting period: water deficiency in the circuit (flow/return spread too large)