BoilerFaultCodes Connection
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Glow-worm Energy2 30c Fault codes & diagnostics
87 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Combi Gas 2018-present
GC Number 47-019-38
Download the Glow-worm Energy2 30c manual
PDF
Versions & GC numbers
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Severity at a glance
Each cell = one fault code. Hover to identify. 87 Unrated
Which version do you have?
The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 47-019-38 | Energy2 30c -A (P-GB) | 2018–present |
Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.
Just want the most common Glow-worm Energy2 30c faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 87 documented codes
Tap any card for details
F.00
Fault: Flow temperature sensor
F.01
Fault: Return temperature sensor
F.10
Short circuit: Flow temperature sensor
F.11
Short circuit: Return temperature sensor
F.12
Short circuit: Cylinder temperature sensor
F.13
Short circuit: Temperature sensor for the domestic hot water cylinder
F.20
Safety shutdown: Overheating temperature reached
F.22
Safety shutdown: Water deficiency in the boiler
F.23
Safety shutdown: Temperature spread too great (NTC1/NTC2)
Showing 11–20 of 87
F.24
Safety shutdown: Temperature rise too fast
F.25
Safety shutdown: Flue gas temperature too high
F.27
Safety shutdown: Fault in flame detection
F.28
Fault: Ignition unsuccessful when starting up
F.29
Fault: Flame loss
F.32
Fan frost protection function active: Fan speed outside the tolerance values
F.49
eBUS fault: Voltage too low
F.61
Fault: Gas valve assembly control
F.62
Fault: Gas valve switch-off control
F.63
Fault: EEPROM
Showing 21–30 of 87
F.64
Fault: Electronics/sensor/analogue-to-digital converter
F.65
Fault: Electronics temperature too high
F.67
Values sent back by ASIC is incorrect (flame signal)
F.68
Fault: Unstable flame (analogue input)
F.70
Invalid product code (DSN)
F.71
Fault: Flow/return temperature sensor
F.72
Fault: Deviation in the water pressure sensor/return temperature sensor
F.73
Fault: Water pressure sensor not connected or has short-circuited
F.74
Fault: Electrical problem in the water pressure sensor
F.75
Fault: Pressure sensor
Showing 31–40 of 87
F.76
The safety cut-out in the primary heat exchanger is defective
F.77
Fault: Condensate or smoke
F.78
Interruption to DHW outlet sensor at external control
F.83
Fault: Dryfire; Whentheburnerstarts,thetemperaturechangeregisteredattheflowor returntemperaturesensorisnon-existentortoosmall
F.84
Fault: Flow/returntemperaturesensor; Valuesnotconsistent,difference<-6K
F.85
Fault: Temperaturesensor; Theflowand/orreturntemperaturesensorshavebeeninstalledonthesame pipe/incorrectpipe
F.86
Fault: Underfloorheatingcontact; Underfloorheatingcontactopen,sensordisconnectedordefective
F.87
Fault: Electrodes; Electrodesnotconnectedortheyareconnectedincorrectly,shortcircuitinthecableharness
F.88
Fault: Gasvalveassembly; Gasvalveassemblynotconnectedoritisconnectedincorrectly,shortcircuit inthecableharness
F.89
Fault: Pump; Pumpnotconnectedoritisconnectedincorrectly,incorrectpumpconnec- ted,shortcircuitinthecableharness
Showing 41–50 of 87
F.91
Short circuit: Cylinder temperature sensor
F.97
Fault: MainPCBself-testfailed; MainPCBdefective
F22
Low water pressure (product switches off)
S.0
Heating mode: No requirement
S.01
Heating mode: Fan prerun
S.02
Heating mode: Pump prerun
S.03
Heating mode: Burner ignition
S.04
Heating mode: Burner on
S.05
Heating mode: Pump/fan overrun
S.06
Heating mode: Fan overrun
Showing 51–60 of 87
S.07
Heating mode: Pump overrun
S.08
Heating mode: Temporary shutdown after heating procedure
S.10
Domestic hot water mode: Requirement
S.11
Domestic hot water mode: Fan prerun
S.13
Domestic hot water mode: Burner ignition
S.14
DHW mode: Burner on
S.15
DHW mode: Pump/fan overrun
S.16
DHW mode: Fan overrun
S.17
DHW mode: Pump overrun
S.20
Domestic hot water mode: Requirement
Showing 61–70 of 87
S.21
Domestic hot water mode: Fan prerun
S.22
Domestic hot water mode: Pump prerun
S.23
Domestic hot water mode: Burner ignition
S.24
DHW mode: Burner on
S.25
DHW mode: Pump/fan overrun
S.26
DHW mode: Fan overrun
S.27
DHW mode: Pump overrun
S.28
Domestic hot water mode: Temporary shutdown of the burner
S.30
Room thermostat is blocking heating mode.
S.31
No heating demand: Summer mode, eBUS control, waiting period
Showing 71–80 of 87
S.32
Fan waiting time: Fan speed outside of the tolerance values
S.33
Forced fan operation until the pressure monitor is switched
S.34
Frost protection active
S.39
Underfloor heating contact open
S.41
Water pressure too high
S.42
Flue non-return flap closed
S.46
Frost protection mode (Comfort): Minimum load
S.53
Product in waiting period/operating block function due to water deficiency (flow/return spread too large)
S.54
Waiting period: Water deficiency in the circuit (flow/return spread too large)
S.76
Maintenance message: Check the water pressure
Showing 81–87 of 87
S.88
Product purging active
S.91
Maintenance: Demo mode
S.96
Automatic test programme: Return temperature sensor, heating demands blocked.
S.97
Automatic test programme: Water pressure sensor, heating demands blocked.
S.98
Automatic test programme: Return temperature sensor, heating demands blocked.
S.99
Internal automatic test programmes
S.108
Purging the combustion cha
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