How do I register a Glow Worm Betacom 4 24c-A with BoilerTag?

To register a Glow Worm Betacom 4 24c-A with BoilerTag, scan the QR code on the BoilerTag sticker after installation. Confirm the pre-filled model details, then record the installation date and your Gas Safe number. This creates a permanent, publicly viewable service log for the appliance. Every future service entry will also be recorded. The first 12 BoilerTag stickers are free for engineers. Order free BoilerTag stickers from the engineer dashboard.

What is the warranty on a Glow Worm Betacom 4 24c-A?

The standard warranty period for the Glow Worm Betacom 4 24c-A is not specified in the available data. However, warranty registration is required to activate any applicable manufacturer's guarantee. Consult the appliance documentation or manufacturer's website for current warranty terms.

How efficient is the Glow Worm Betacom 4 24c-A?

The Glow Worm Betacom 4 24c-A has a seasonal efficiency of 98.9%. It also achieves a part-load efficiency of 109.8%, indicating efficient operation under varied demand. This model is rated as NOx Class 5 for low nitrogen oxide emissions.

What does fault code F.22 mean on a Glow Worm Betacom 4 24c-A?

Fault code F.22 on the Glow Worm Betacom 4 24c-A indicates a safety shutdown due to water deficiency in the boiler. This can be caused by insufficient water, a defective water pressure sensor, or a loose/defective cable to the pump or sensor. This is a lockout fault.

What are the other models in the Glow Worm Betacom 4 range?

The Glow Worm Betacom 4 range includes the 24c-A, which provides a 24 kW domestic hot water output, and the Betacom 4 30c-A, offering a higher 30 kW domestic hot water output. Both are natural gas combi boilers.

What does fault code F.00 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Flow temperature sensor Likely causes: NTC plug not plugged in or has come loose; multiple plug on the PCB not plugged in correctly; interruption in cable harness; NTC sensor defective.

What does fault code F.01 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Return temperature sensor Likely causes: NTC plug not plugged in or has come loose; multiple plug on the PCB not plugged in correctly; interruption in cable harness; NTC sensor defective.

What does fault code F.10 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Short circuit: Flow temperature sensor Likely causes: NTC sensor defective; short circuit in the cable harness; cable/housing.

What does fault code F.11 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Short circuit: Return temperature sensor Likely causes: NTC sensor defective; short circuit in the cable harness; cable/housing.

What does fault code F.13 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Short circuit: Domestic hot water cylinder temperature sensor Likely causes: NTC sensor defective; short circuit in the cable harness; cable/housing.

What does fault code F.20 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Overheating temperat-ure reached Likely causes: Incorrect earth connection between cable harness and product; flow or return NTC defective (loose connection); stray spark via ignition cable; ignition plug or ignition electrode.

What does fault code F.22 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Water deficiency in the boiler Likely causes: No or insufficient water in the product; water pressure sensor defective; cable to the pump or to the water pressure sensor loose/not connected/defective.

What does fault code F.23 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Temperature spread too great (NTC1/NTC2) Likely causes: Pump blocked; insufficient pump output; air in product; flow and return NTC connected the wrong way round.

What does fault code F.24 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Temperature rise too fast Likely causes: Pump blocked; reduced pump output; air in product; system pressure too low; non-return valve blocked/incorrectly installed.

What does fault code F.25 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Flue gas temperature too high Likely causes: Break in plug connection for optional flue gas safety cut-out (SCO); break in cable harness.

What does fault code F.27 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Safety shutdown: Fault in flame detec-tion Likely causes: Moisture on the electronics; electronics (flame monitor) defective; gas solenoid valve leaking.

What does fault code F.28 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Ignition unsuccessful when starting up Likely causes: Gas meter defective or gas pressure monitor has triggered; air in gas; gas flow pressure too low; thermal isolator device (TAE) has triggered; incorrect gas injector; incorrect spare gas valve assembly; fault on the gas valve assembly; mu…

What does fault code F.29 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Flame loss Likely causes: Gas supply temporarily stopped; flue gas recirculation; incorrect earthing of product; ignition transformer has spark failure.

What does fault code F.32 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fan frost protection function active: Fan speed outside the tolerance values Likely causes: Plug on fan not correctly plugged in; multiple plug on PCB not correctly plugged in; break in cable harness; fan blocked; Hall sensor defective; electronics defective.

What does fault code F.49 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

eBUS fault: Voltage too low Likely causes: Short circuit on eBUS; eBUS overload or two power supplies with different polarities on the eBUS.

What does fault code F.61 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Gas valve assembly control Likely causes: Short circuit/short to earth in cable harness for the gas valve assembly; gas valve assembly defective (coils shorted to earth); electronics defective.

What does fault code F.62 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Gas valve switch-off control Likely causes: Delayed switch-off of gas valve assembly; delayed extinguishing of flame signal; gas valve assembly leaking; electronics defective.

What does fault code F.63 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: EEPROM Likely causes: Electronics defective.

What does fault code F.64 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Electronics/sensor/analogue-to-digital converter Likely causes: Flow or return NTC short circuited; electronics defective.

What does fault code F.65 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Electronics temperature too high Likely causes: Electronics overheating due to external influences; electronics defective.

What does fault code F.67 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Value sent back by ASIC is incorrect (flame signal) Likely causes: Implausible flame signal; electronics defective.

What does fault code F.68 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Unstable flame (analogue input) Likely causes: Air in gas; gas flow pressure too low; incorrect air ratio; incorrect gas injector; ionisation flow interruption (cable, electrode).

What does fault code F.70 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Invalid product code (DSN) Likely causes: Replace the screen and PCB at the same time without reconfiguring the product's Device Specific Number.

What does fault code F.71 mean on the Glow Worm BETACOM 4 24c -A (H-GB)?

Fault: Flow/return temperature sensor Likely causes: Flow temperature sensor specifies a constant value: Flow temperature sensor incorrectly attached to the flow pipe; flow temperature sensor defective.

← Browse all Glow Worm boilers

Glow Worm

BETACOM 4 24c -A (H-GB)

The Glow Worm Betacom 4 24c-A is a 24 kW natural gas combi boiler with a seasonal efficiency of 98.9% and a domestic hot water flow rate of 11.7 litres per minute at a 30°C temperature rise.

The Glow Worm Betacom 4 24c-A is a wall-hung natural gas condensing combi boiler designed for domestic heating and hot water provision in UK properties. This reference page provides detailed technical specifications, installation parameters, and a comprehensive list of fault codes. It serves as a resource for gas engineers and homeowners seeking specific information regarding the Betacom 4 24c-A model, covering performance data, physical attributes, and operational diagnostics.

CH output: 20.2 kW
DHW flow (∆30°C): 11.7 L/min
NOx class: 5

BETACOM 4 24c -A (H-GB) at a glance

Type: combi · natural_gas
Output: 20.2 kW heating · 24.7 kW hot water
Efficiency: 98.9% seasonal
DHW flow rate: 11.7 L/min @ Δ30°C
Dimensions: 740 × 418 × 300 mm · 32 kg
Manufacturer: Glow-worm

Register this Glow Worm BETACOM 4 24c -A (H-GB) on BoilerTag

Stick a QR tag on the case, scan it on every service and give your customer a permanent, shareable service history they can pull up from any phone.

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One QR scan on the boiler surfaces every previous fault, part change and visit — no paperwork to dig out.
Free AI fault diagnostics, built in
Every tag you fit unlocks the AI diagnostic tool for that exact model — paste a fault code, get a ranked cause list.
Your name on the boiler forever
When the next service or breakdown comes around the homeowner scans and sees your number first.
First 12 BoilerTags are free
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BETACOM 4 24c -A (H-GB) data sheet

Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.

Identification▼

Model name: Betacom 4
Manufacturer: Glow-worm
Product family: Betacom 4

Type & fuel▼

Boiler type: Combi
Fuel: Natural gas
Condensing: Yes
Mounting: Wall-hung

Output▼

CH output (min): 5 kW
CH output (max): 20.2 kW
DHW output (min): 5.1 kW
DHW output (max): 24.7 kW

Domestic hot water▼

Flow rate (∆T 30°C): 11.7 L/min
Flow rate (∆T 35°C): 10 L/min
DHW temperature range: 35-60
Legionella cycle: Yes

Efficiency▼

Seasonal efficiency: 98.9 %
NOx class: 5
Part-load efficiency: 109.8 %

Physical dimensions▼

Height: 740 mm
Width: 418 mm
Depth: 300 mm
Weight (dry): 32 kg
Weight (filled): 36 kg

Connections▼

Flow pipe: 19.05 mm
Return pipe: 19.05 mm
Gas pipe: 12.7 mm
Cold mains: 19.05 mm
DHW outlet: 19.05 mm
Condensate drain: 21.5 mm

Gas▼

Natural gas inlet: 20 mbar
Max gas rate (NG): 2.6 m³/h

Water & pressures▼

Max operating pressure: 2.5 bar
Max DHW pressure: 10 bar
EV pre-charge: 0.75 bar
PRV setting: 3 bar

Electrical▼

Voltage: 230 V
Frequency: 50 Hz
Max power: 105 W
Standby power: 2 W
Fuse rating: 2 A
IP rating: IPX4D

Flue▼

Flue types: concentric, plume_management
Flue sizes: 60/100, 80/125 mm
Max horizontal flue: 25 m
Max vertical flue: 25 m

Heat exchanger▼

Secondary type: plate

Pump▼

Pump type: high_efficiency

Controls▼

Built-in timer: Yes

Safety▼

Safety devices: overheat, flame_failure, prv, low_water, frost_protection
Frost protection: Yes
Ignition type: electronic

Installation▼

Clearance (sides): 50 mm

pH value between 6.5 and 8.5, free of sedimentary materials, magnetite, oxygen

Warranty▼

Registration required: Yes

Compliance▼

CE / UKCA marked: Yes

Engineer's overview

The Glow Worm Betacom 4 24c-A is a natural gas combi boiler providing a maximum central heating output of 20.2 kW and a domestic hot water output of 24.7 kW. This wall-hung condensing unit delivers a DHW flow rate of 11.7 litres per minute at a 30°C temperature rise, suitable for standard UK household demands. It achieves a seasonal efficiency of 98.9% and has a NOx Class 5 rating, indicating low nitrogen oxide emissions. Physical dimensions are 740mm (H) x 418mm (W) x 300mm (D), with a dry weight of 32 kg. The appliance operates at a natural gas inlet pressure of 20 mbar and includes integrated frost protection. Installation requires specific clearances, notably 50mm on the sides, and adherence to water quality guidelines for optimal performance.

BETACOM 4 24c -A (H-GB) fault codes

Every fault code listed in the manufacturer brochure, with likely causes and engineer actions. Each code has a permalink — paste a URL like https://www.boilertag.com/boilers/glow-worm/betacom-4-24c-a-h-gb#fault-f.00 to jump straight to the entry.

Complete list of fault codes for this Glow Worm BETACOM 4 24c -A (H-GB)
Code	Meaning	Details
F.00	Fault: Flow temperature sensor Show causes & actions Likely causes NTC plug not plugged in or has come loose multiple plug on the PCB not plugged in correctly interruption in cable harness NTC sensor defective	Details
F.01	Fault: Return temperature sensor Show causes & actions Likely causes NTC plug not plugged in or has come loose multiple plug on the PCB not plugged in correctly interruption in cable harness NTC sensor defective	Details
F.10	Short circuit: Flow temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.11	Short circuit: Return temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.13	Short circuit: Domestic hot water cylinder temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.20Lockout	Safety shutdown: Overheating temperat-ure reached Show causes & actions Likely causes Incorrect earth connection between cable harness and product flow or return NTC defective (loose connection) stray spark via ignition cable ignition plug or ignition electrode	Details
F.22Lockout	Safety shutdown: Water deficiency in the boiler Show causes & actions Likely causes No or insufficient water in the product water pressure sensor defective cable to the pump or to the water pressure sensor loose/not connected/defective	Details
F.23Lockout	Safety shutdown: Temperature spread too great (NTC1/NTC2) Show causes & actions Likely causes Pump blocked insufficient pump output air in product flow and return NTC connected the wrong way round	Details
F.24Lockout	Safety shutdown: Temperature rise too fast Show causes & actions Likely causes Pump blocked reduced pump output air in product system pressure too low non-return valve blocked/incorrectly installed	Details
F.25Lockout	Safety shutdown: Flue gas temperature too high Show causes & actions Likely causes Break in plug connection for optional flue gas safety cut-out (SCO) break in cable harness	Details
F.27Lockout	Safety shutdown: Fault in flame detec-tion Show causes & actions Likely causes Moisture on the electronics electronics (flame monitor) defective gas solenoid valve leaking	Details
F.28	Fault: Ignition unsuccessful when starting up Show causes & actions Likely causes Gas meter defective or gas pressure monitor has triggered air in gas gas flow pressure too low thermal isolator device (TAE) has triggered incorrect gas injector incorrect spare gas valve assembly fault on the gas valve assembly multiple plug on PCB incorrectly plugged in break in cable harness ignition system (ignition transformer, ignition cable, ignition plug, ignition electrode) defective ionisation flow interrupted (cable, electrode) incorrect earthing of product electronics defective	Details
F.29	Fault: Flame loss Show causes & actions Likely causes Gas supply temporarily stopped flue gas recirculation incorrect earthing of product ignition transformer has spark failure	Details
F.32	Fan frost protection function active: Fan speed outside the tolerance values Show causes & actions Likely causes Plug on fan not correctly plugged in multiple plug on PCB not correctly plugged in break in cable harness fan blocked Hall sensor defective electronics defective	Details
F.49	eBUS fault: Voltage too low Show causes & actions Likely causes Short circuit on eBUS eBUS overload or two power supplies with different polarities on the eBUS	Details
F.61	Fault: Gas valve assembly control Show causes & actions Likely causes Short circuit/short to earth in cable harness for the gas valve assembly gas valve assembly defective (coils shorted to earth) electronics defective	Details
F.62	Fault: Gas valve switch-off control Show causes & actions Likely causes Delayed switch-off of gas valve assembly delayed extinguishing of flame signal gas valve assembly leaking electronics defective	Details
F.63	Fault: EEPROM Show causes & actions Likely causes Electronics defective	Details
F.64	Fault: Electronics/sensor/analogue-to-digital converter Show causes & actions Likely causes Flow or return NTC short circuited electronics defective	Details
F.65	Fault: Electronics temperature too high Show causes & actions Likely causes Electronics overheating due to external influences electronics defective	Details
F.67	Value sent back by ASIC is incorrect (flame signal) Show causes & actions Likely causes Implausible flame signal electronics defective	Details
F.68	Fault: Unstable flame (analogue input) Show causes & actions Likely causes Air in gas gas flow pressure too low incorrect air ratio incorrect gas injector ionisation flow interruption (cable, electrode)	Details
F.70	Invalid product code (DSN) Show causes & actions Likely causes Replace the screen and PCB at the same time without reconfiguring the product's Device Specific Number	Details
F.71	Fault: Flow/return temperature sensor Show causes & actions Likely causes Flow temperature sensor specifies a constant value: Flow temperature sensor incorrectly attached to the flow pipe flow temperature sensor defective	Details
F.72	Fault: Deviation in the water pressure sensor/return temperature sensor Show causes & actions Likely causes Flow/return NTC temperature difference too great – flow and/or return temperature sensor defective	Details
F.73	Fault: Water pressure sensor not con-nected or has short-circuited Show causes & actions Likely causes Interruption/short circuit of water pressure sensor interruption/short to earth in supply pipe to water pressure sensor or water pressure sensor defective	Details
F.74	Fault: Electrical problem in the water pressure sensor Show causes & actions Likely causes Line to water pressure sensor has a short circuit to 5 V/24 V or internal fault in the water pressure sensor	Details
F.75	Fault: Pressure sensor Show causes & actions Likely causes Pressure sensor or pump defective or water deficiency	Details
F.77	Fault: Condensate or smoke Show causes & actions Likely causes No response flue non-return flap defective	Details
F.78	Interruption to DHW outlet sensor at the external control Show causes & actions Likely causes Link box connected, but domestic hot water NTC not bridged	Details
F.83	Fault: Dry fire Show causes & actions Likely causes When the burner starts, the temperature change recorded by the flow or return temperature sensor is non-existent or too small: Insufficient water in the product flow or return temperature sensor incorrectly attached to the pipe	Details
F.84	Fault: Flow/return temperature sensor Show causes & actions Likely causes Values not consistent difference < -6 K Flow and return temperature sensors signalling implausible values: Flow and return temperature sensors have been inverted flow and return temperature sensors have not been correctly installed	Details
F.85	Fault: Temperature sensor Show causes & actions Likely causes The flow and/or return temperature sensors have been installed on the same pipe/incorrect pipe	Details
F.86	Fault: Underfloor heating contact Show causes & actions Likely causes Underfloor heating contact open sensor disconnected or defective	Details
F.87	Fault: Ignition electrode Show causes & actions Likely causes Ignition electrode not connected properly short circuit in the cable harness	Details
F.88	Fault: Gas valve assembly Show causes & actions Likely causes Gas valve assembly not connected or it is connected incorrectly short circuit in the cable harness	Details
F.89	Fault: Pump Show causes & actions Likely causes Pump not connected or it is connected incorrectly incorrect pump connected short circuit in the cable harness	Details

Common BETACOM 4 24c -A (H-GB) problems & troubleshooting

Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: overheating temperat-ure reachedLockout

Triggered by fault code F.20.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: water deficiency in the boilerLockout

Triggered by fault code F.22.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature spread too great (ntc1/ntc2)Lockout

Triggered by fault code F.23.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature rise too fastLockout

Triggered by fault code F.24.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: flue gas temperature too highLockout

Triggered by fault code F.25.

Likely causes that trigger multiple BETACOM 4 24c -A (H-GB) fault codes

Electronics defective: Fault codes: F.28, F.32, F.61, F.62, F.63, F.64, F.65, F.67
Short circuit in the cable harness: Fault codes: F.10, F.11, F.13, F.87, F.88, F.89
Ntc sensor defective: Fault codes: F.00, F.01, F.10, F.11, F.13
Break in cable harness: Fault codes: F.25, F.28, F.32
Cable/housing: Fault codes: F.10, F.11, F.13
Air in gas: Fault codes: F.28, F.68
Air in product: Fault codes: F.23, F.24
Gas flow pressure too low: Fault codes: F.28, F.68
Incorrect earthing of product: Fault codes: F.28, F.29
Incorrect gas injector: Fault codes: F.28, F.68
Interruption in cable harness: Fault codes: F.00, F.01
Multiple plug on the pcb not plugged in correctly: Fault codes: F.00, F.01

Real-world Glow Worm fault diagnostics

Diagnostic checklists from engineer-submitted Glow Worm faults, with step-by-step checks and safety notes.

Energy 25c — fault F.32 →
The Glow Worm Energy 25c displaying fault code F.32, with the fan cycling erratically and making a struggling humming noise, indicates an…
Energy 25c — fault F.28 →
The Glow Worm Energy 25c displaying an F.28 fault code indicates an ignition failure.

Browse all Glow Worm fault diagnostics →

BETACOM 4 24c -A (H-GB) FAQs

Common questions from engineers and homeowners about the Glow Worm BETACOM 4 24c -A (H-GB).

How do I register a Glow Worm Betacom 4 24c-A with BoilerTag?: To register a Glow Worm Betacom 4 24c-A with BoilerTag, scan the QR code on the BoilerTag sticker after installation. Confirm the pre-filled model details, then record the installation date and your Gas Safe number. This creates a permanent, publicly viewable service log for the appliance. Every future service entry will also be recorded. The first 12 BoilerTag stickers are free for engineers. Order free BoilerTag stickers from the engineer dashboard.
What is the Glow Worm Betacom 4 24c-A?: The Glow Worm Betacom 4 24c-A is a 24 kW natural gas combi boiler with a 98.9% seasonal efficiency and a domestic hot water flow rate of 11.7 litres per minute at a 30°C temperature rise. It is designed for wall-hung installation in UK domestic properties.
What is the warranty on a Glow Worm Betacom 4 24c-A?: The standard warranty period for the Glow Worm Betacom 4 24c-A is not specified in the available data. However, warranty registration is required to activate any applicable manufacturer's guarantee. Consult the appliance documentation or manufacturer's website for current warranty terms.

Every boiler brochure, free with BoilerTag

We hold the Glow Worm BETACOM 4 24c -A (H-GB) manual — and every other UK boiler and heat pump brochure. Sign up and pull any model up from your phone, on the job.

Working on a Glow Worm BETACOM 4 24c -A (H-GB)?

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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 28 June 2026.

← Browse all Glow Worm boilers

Glow Worm

BETACOM 4 24c -A (H-GB)

The Glow Worm Betacom 4 24c-A is a 24 kW natural gas combi boiler with a seasonal efficiency of 98.9% and a domestic hot water flow rate of 11.7 litres per minute at a 30°C temperature rise.

CH output: 20.2 kW
DHW flow (∆30°C): 11.7 L/min
NOx class: 5

BETACOM 4 24c -A (H-GB) at a glance

Type: combi · natural_gas
Output: 20.2 kW heating · 24.7 kW hot water
Efficiency: 98.9% seasonal
DHW flow rate: 11.7 L/min @ Δ30°C
Dimensions: 740 × 418 × 300 mm · 32 kg
Manufacturer: Glow-worm

Register this Glow Worm BETACOM 4 24c -A (H-GB) on BoilerTag

Stick a QR tag on the case, scan it on every service and give your customer a permanent, shareable service history they can pull up from any phone.

Permanent, shareable service history
One QR scan on the boiler surfaces every previous fault, part change and visit — no paperwork to dig out.
Free AI fault diagnostics, built in
Every tag you fit unlocks the AI diagnostic tool for that exact model — paste a fault code, get a ranked cause list.
Your name on the boiler forever
When the next service or breakdown comes around the homeowner scans and sees your number first.
First 12 BoilerTags are free
Tag every install and service you do from now on — the subscription only kicks in once you scale past your first dozen.

Diagnosing a fault on a Glow Worm BETACOM 4 24c -A (H-GB) right now?

Try the free AI fault diagnostics tool — no signup needed.

Open the diagnostics tool →

BETACOM 4 24c -A (H-GB) data sheet

Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.

Identification▼

Model name: Betacom 4
Manufacturer: Glow-worm
Product family: Betacom 4

Type & fuel▼

Boiler type: Combi
Fuel: Natural gas
Condensing: Yes
Mounting: Wall-hung

Output▼

CH output (min): 5 kW
CH output (max): 20.2 kW
DHW output (min): 5.1 kW
DHW output (max): 24.7 kW

Domestic hot water▼

Flow rate (∆T 30°C): 11.7 L/min
Flow rate (∆T 35°C): 10 L/min
DHW temperature range: 35-60
Legionella cycle: Yes

Efficiency▼

Seasonal efficiency: 98.9 %
NOx class: 5
Part-load efficiency: 109.8 %

Physical dimensions▼

Height: 740 mm
Width: 418 mm
Depth: 300 mm
Weight (dry): 32 kg
Weight (filled): 36 kg

Connections▼

Flow pipe: 19.05 mm
Return pipe: 19.05 mm
Gas pipe: 12.7 mm
Cold mains: 19.05 mm
DHW outlet: 19.05 mm
Condensate drain: 21.5 mm

Gas▼

Natural gas inlet: 20 mbar
Max gas rate (NG): 2.6 m³/h

Water & pressures▼

Max operating pressure: 2.5 bar
Max DHW pressure: 10 bar
EV pre-charge: 0.75 bar
PRV setting: 3 bar

Electrical▼

Voltage: 230 V
Frequency: 50 Hz
Max power: 105 W
Standby power: 2 W
Fuse rating: 2 A
IP rating: IPX4D

Flue▼

Flue types: concentric, plume_management
Flue sizes: 60/100, 80/125 mm
Max horizontal flue: 25 m
Max vertical flue: 25 m

Heat exchanger▼

Secondary type: plate

Pump▼

Pump type: high_efficiency

Controls▼

Built-in timer: Yes

Safety▼

Safety devices: overheat, flame_failure, prv, low_water, frost_protection
Frost protection: Yes
Ignition type: electronic

Installation▼

Clearance (sides): 50 mm

pH value between 6.5 and 8.5, free of sedimentary materials, magnetite, oxygen

Warranty▼

Registration required: Yes

Compliance▼

CE / UKCA marked: Yes

Engineer's overview

BETACOM 4 24c -A (H-GB) fault codes

Complete list of fault codes for this Glow Worm BETACOM 4 24c -A (H-GB)
Code	Meaning	Details
F.00	Fault: Flow temperature sensor Show causes & actions Likely causes NTC plug not plugged in or has come loose multiple plug on the PCB not plugged in correctly interruption in cable harness NTC sensor defective	Details
F.01	Fault: Return temperature sensor Show causes & actions Likely causes NTC plug not plugged in or has come loose multiple plug on the PCB not plugged in correctly interruption in cable harness NTC sensor defective	Details
F.10	Short circuit: Flow temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.11	Short circuit: Return temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.13	Short circuit: Domestic hot water cylinder temperature sensor Show causes & actions Likely causes NTC sensor defective short circuit in the cable harness cable/housing	Details
F.20Lockout	Safety shutdown: Overheating temperat-ure reached Show causes & actions Likely causes Incorrect earth connection between cable harness and product flow or return NTC defective (loose connection) stray spark via ignition cable ignition plug or ignition electrode	Details
F.22Lockout	Safety shutdown: Water deficiency in the boiler Show causes & actions Likely causes No or insufficient water in the product water pressure sensor defective cable to the pump or to the water pressure sensor loose/not connected/defective	Details
F.23Lockout	Safety shutdown: Temperature spread too great (NTC1/NTC2) Show causes & actions Likely causes Pump blocked insufficient pump output air in product flow and return NTC connected the wrong way round	Details
F.24Lockout	Safety shutdown: Temperature rise too fast Show causes & actions Likely causes Pump blocked reduced pump output air in product system pressure too low non-return valve blocked/incorrectly installed	Details
F.25Lockout	Safety shutdown: Flue gas temperature too high Show causes & actions Likely causes Break in plug connection for optional flue gas safety cut-out (SCO) break in cable harness	Details
F.27Lockout	Safety shutdown: Fault in flame detec-tion Show causes & actions Likely causes Moisture on the electronics electronics (flame monitor) defective gas solenoid valve leaking	Details
F.28	Fault: Ignition unsuccessful when starting up Show causes & actions Likely causes Gas meter defective or gas pressure monitor has triggered air in gas gas flow pressure too low thermal isolator device (TAE) has triggered incorrect gas injector incorrect spare gas valve assembly fault on the gas valve assembly multiple plug on PCB incorrectly plugged in break in cable harness ignition system (ignition transformer, ignition cable, ignition plug, ignition electrode) defective ionisation flow interrupted (cable, electrode) incorrect earthing of product electronics defective	Details
F.29	Fault: Flame loss Show causes & actions Likely causes Gas supply temporarily stopped flue gas recirculation incorrect earthing of product ignition transformer has spark failure	Details
F.32	Fan frost protection function active: Fan speed outside the tolerance values Show causes & actions Likely causes Plug on fan not correctly plugged in multiple plug on PCB not correctly plugged in break in cable harness fan blocked Hall sensor defective electronics defective	Details
F.49	eBUS fault: Voltage too low Show causes & actions Likely causes Short circuit on eBUS eBUS overload or two power supplies with different polarities on the eBUS	Details
F.61	Fault: Gas valve assembly control Show causes & actions Likely causes Short circuit/short to earth in cable harness for the gas valve assembly gas valve assembly defective (coils shorted to earth) electronics defective	Details
F.62	Fault: Gas valve switch-off control Show causes & actions Likely causes Delayed switch-off of gas valve assembly delayed extinguishing of flame signal gas valve assembly leaking electronics defective	Details
F.63	Fault: EEPROM Show causes & actions Likely causes Electronics defective	Details
F.64	Fault: Electronics/sensor/analogue-to-digital converter Show causes & actions Likely causes Flow or return NTC short circuited electronics defective	Details
F.65	Fault: Electronics temperature too high Show causes & actions Likely causes Electronics overheating due to external influences electronics defective	Details
F.67	Value sent back by ASIC is incorrect (flame signal) Show causes & actions Likely causes Implausible flame signal electronics defective	Details
F.68	Fault: Unstable flame (analogue input) Show causes & actions Likely causes Air in gas gas flow pressure too low incorrect air ratio incorrect gas injector ionisation flow interruption (cable, electrode)	Details
F.70	Invalid product code (DSN) Show causes & actions Likely causes Replace the screen and PCB at the same time without reconfiguring the product's Device Specific Number	Details
F.71	Fault: Flow/return temperature sensor Show causes & actions Likely causes Flow temperature sensor specifies a constant value: Flow temperature sensor incorrectly attached to the flow pipe flow temperature sensor defective	Details
F.72	Fault: Deviation in the water pressure sensor/return temperature sensor Show causes & actions Likely causes Flow/return NTC temperature difference too great – flow and/or return temperature sensor defective	Details
F.73	Fault: Water pressure sensor not con-nected or has short-circuited Show causes & actions Likely causes Interruption/short circuit of water pressure sensor interruption/short to earth in supply pipe to water pressure sensor or water pressure sensor defective	Details
F.74	Fault: Electrical problem in the water pressure sensor Show causes & actions Likely causes Line to water pressure sensor has a short circuit to 5 V/24 V or internal fault in the water pressure sensor	Details
F.75	Fault: Pressure sensor Show causes & actions Likely causes Pressure sensor or pump defective or water deficiency	Details
F.77	Fault: Condensate or smoke Show causes & actions Likely causes No response flue non-return flap defective	Details
F.78	Interruption to DHW outlet sensor at the external control Show causes & actions Likely causes Link box connected, but domestic hot water NTC not bridged	Details
F.83	Fault: Dry fire Show causes & actions Likely causes When the burner starts, the temperature change recorded by the flow or return temperature sensor is non-existent or too small: Insufficient water in the product flow or return temperature sensor incorrectly attached to the pipe	Details
F.84	Fault: Flow/return temperature sensor Show causes & actions Likely causes Values not consistent difference < -6 K Flow and return temperature sensors signalling implausible values: Flow and return temperature sensors have been inverted flow and return temperature sensors have not been correctly installed	Details
F.85	Fault: Temperature sensor Show causes & actions Likely causes The flow and/or return temperature sensors have been installed on the same pipe/incorrect pipe	Details
F.86	Fault: Underfloor heating contact Show causes & actions Likely causes Underfloor heating contact open sensor disconnected or defective	Details
F.87	Fault: Ignition electrode Show causes & actions Likely causes Ignition electrode not connected properly short circuit in the cable harness	Details
F.88	Fault: Gas valve assembly Show causes & actions Likely causes Gas valve assembly not connected or it is connected incorrectly short circuit in the cable harness	Details
F.89	Fault: Pump Show causes & actions Likely causes Pump not connected or it is connected incorrectly incorrect pump connected short circuit in the cable harness	Details

Common BETACOM 4 24c -A (H-GB) problems & troubleshooting

Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: overheating temperat-ure reachedLockout

Triggered by fault code F.20.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: water deficiency in the boilerLockout

Triggered by fault code F.22.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature spread too great (ntc1/ntc2)Lockout

Triggered by fault code F.23.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature rise too fastLockout

Triggered by fault code F.24.

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: flue gas temperature too highLockout

Triggered by fault code F.25.

Likely causes that trigger multiple BETACOM 4 24c -A (H-GB) fault codes

Electronics defective: Fault codes: F.28, F.32, F.61, F.62, F.63, F.64, F.65, F.67
Short circuit in the cable harness: Fault codes: F.10, F.11, F.13, F.87, F.88, F.89
Ntc sensor defective: Fault codes: F.00, F.01, F.10, F.11, F.13
Break in cable harness: Fault codes: F.25, F.28, F.32
Cable/housing: Fault codes: F.10, F.11, F.13
Air in gas: Fault codes: F.28, F.68
Air in product: Fault codes: F.23, F.24
Gas flow pressure too low: Fault codes: F.28, F.68
Incorrect earthing of product: Fault codes: F.28, F.29
Incorrect gas injector: Fault codes: F.28, F.68
Interruption in cable harness: Fault codes: F.00, F.01
Multiple plug on the pcb not plugged in correctly: Fault codes: F.00, F.01

Real-world Glow Worm fault diagnostics

Diagnostic checklists from engineer-submitted Glow Worm faults, with step-by-step checks and safety notes.

Energy 25c — fault F.32 →
The Glow Worm Energy 25c displaying fault code F.32, with the fan cycling erratically and making a struggling humming noise, indicates an…
Energy 25c — fault F.28 →
The Glow Worm Energy 25c displaying an F.28 fault code indicates an ignition failure.

Browse all Glow Worm fault diagnostics →

BETACOM 4 24c -A (H-GB) FAQs

Common questions from engineers and homeowners about the Glow Worm BETACOM 4 24c -A (H-GB).

How do I register a Glow Worm Betacom 4 24c-A with BoilerTag?: To register a Glow Worm Betacom 4 24c-A with BoilerTag, scan the QR code on the BoilerTag sticker after installation. Confirm the pre-filled model details, then record the installation date and your Gas Safe number. This creates a permanent, publicly viewable service log for the appliance. Every future service entry will also be recorded. The first 12 BoilerTag stickers are free for engineers. Order free BoilerTag stickers from the engineer dashboard.
What is the Glow Worm Betacom 4 24c-A?: The Glow Worm Betacom 4 24c-A is a 24 kW natural gas combi boiler with a 98.9% seasonal efficiency and a domestic hot water flow rate of 11.7 litres per minute at a 30°C temperature rise. It is designed for wall-hung installation in UK domestic properties.
What is the warranty on a Glow Worm Betacom 4 24c-A?: The standard warranty period for the Glow Worm Betacom 4 24c-A is not specified in the available data. However, warranty registration is required to activate any applicable manufacturer's guarantee. Consult the appliance documentation or manufacturer's website for current warranty terms.

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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 28 June 2026.

BETACOM 4 24c -A (H-GB) at a glance

Register this Glow Worm BETACOM 4 24c -A (H-GB) on BoilerTag

BETACOM 4 24c -A (H-GB) data sheet

Engineer's overview

BETACOM 4 24c -A (H-GB) fault codes

Common BETACOM 4 24c -A (H-GB) problems & troubleshooting

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: overheating temperat-ure reachedLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: water deficiency in the boilerLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature spread too great (ntc1/ntc2)Lockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature rise too fastLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: flue gas temperature too highLockout

Likely causes that trigger multiple BETACOM 4 24c -A (H-GB) fault codes

Real-world Glow Worm fault diagnostics

BETACOM 4 24c -A (H-GB) FAQs

How efficient is the Glow Worm Betacom 4 24c-A?

What does fault code F.22 mean on a Glow Worm Betacom 4 24c-A?

What are the other models in the Glow Worm Betacom 4 range?

Every boiler brochure, free with BoilerTag

Other Glow Worm boilers

Working on a Glow Worm BETACOM 4 24c -A (H-GB)?

BETACOM 4 24c -A (H-GB) at a glance

Register this Glow Worm BETACOM 4 24c -A (H-GB) on BoilerTag

BETACOM 4 24c -A (H-GB) data sheet

Engineer's overview

BETACOM 4 24c -A (H-GB) fault codes

Common BETACOM 4 24c -A (H-GB) problems & troubleshooting

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: overheating temperat-ure reachedLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: water deficiency in the boilerLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature spread too great (ntc1/ntc2)Lockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: temperature rise too fastLockout

How to fix the BETACOM 4 24c -A (H-GB) safety shutdown: flue gas temperature too highLockout

Likely causes that trigger multiple BETACOM 4 24c -A (H-GB) fault codes

Real-world Glow Worm fault diagnostics

BETACOM 4 24c -A (H-GB) FAQs

How efficient is the Glow Worm Betacom 4 24c-A?

What does fault code F.22 mean on a Glow Worm Betacom 4 24c-A?

What are the other models in the Glow Worm Betacom 4 range?

Every boiler brochure, free with BoilerTag

Other Glow Worm boilers

Working on a Glow Worm BETACOM 4 24c -A (H-GB)?