Glow-worm Energy System fault F.49
EBUS fault: voltage too low
Gas boilerWhat it means
eBUS voltage detected below required level
Likely causes
- Short circuit on eBUS
- EBUS overload
- Two power supplies with different polarities on the eBUS
Where to start
- Read d.80 for heating mode running time (value x100 hours)
- Read d.81 for DHW mode running time (value x100 hours)
- Read d.82 for burner ignitions in heating mode (value x100)
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 51), 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 System. Check the model on the data plate before you order parts.
Other Glow-worm Energy System 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.23Safety shutdown: temperature spread too great (NTC1/NTC2)
- F.24Safety shutdown: temperature rise too fast
- F.25Safety shutdown: flue gas temperature too high
- F.61Fault: gas valve assembly control
- F.62Fault: gas valve switch-off control
- F.70Invalid product code (DSN)
- F.77Fault: condensate or smoke
- F.88Fault: gas valve assembly
- F.89Fault: pump
- S.42Flue non-return flap closed
- S.53Product in waiting period / operating block function due to water deficiency...
- S.54Waiting period: water deficiency in the circuit (flow/return spread too large)