BoilerFaultCodes F.00
Fault: Flow temperature sensor
Glow-worm EASICOM 3 25r Fault codes & diagnostics
44 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Regular Gas 2016-present
GC Number 41-019-50
Download the Glow-worm EASICOM 3 25r 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. 44 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 |
|---|---|---|
| 41-019-50 | EASICOM 3 25r | 2016–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 EASICOM 3 25r faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 44 documented codes
Tap any card for details
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.23
Safety shutdown: Temperature spread too great (NTC1/NTC2)
F.24
Safety shutdown: Temperature rise too fast
F.25
Safety shutdown: Flue gas temperature too high
Showing 11–20 of 44
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
F.64
Fault: Electronics/sensor/analogue-to-digital converter
F.65
Fault: Electronics temperature too high
Showing 21–30 of 44
F.67
Value 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.77
Fault: Condensate or smoke
F.78
Interruption to DHW outlet sensor at external control
F.83
Fault: Dry fire
F.84
Fault: Flow/return temperature sensor
F.85
Fault: Temperature sensor
Showing 31–40 of 44
F.86
Fault: Underfloor heating contact
F.87
Fault: Electrodes
F.88
Fault: Gas valve assembly
F.91
Short circuit: Cylinder temperature sensor
F.97
Fault: Main PCB self-test failed
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
Showing 41–44 of 44
S.05
Heating mode: Pump/fan overrun
S.06
Heating mode: Fan overrun
S.07
Heating mode: Pump overrun
S.08
Heating mode: Temporary shutdown after heating procedure
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