Glow-worm F.54 fault codewhat it means and how to fix it
F.54 on an Energy 35 Store is a gas pressure fault shown with F.28 or F.29: too little gas reaching the boiler, most often a closed gas isolator cock. Only the 35 Store lists it.
Take care
What F.54 means
The Energy 35 Store is the one current Glow-worm built on a board that measures gas flow, and it carries a handful of codes no other Glow-worm range prints. F.54 is the most useful of them to a householder. The 35 Store installation manual defines it as "gas pressure fault (in combination with F.28/F.29)" with two causes: "no or insufficient gas inlet pressure, gas isolator cock closed". So where an Energy7 owner with no gas simply sees F.28 and has to work out why, a 35 Store owner sees F.54 alongside it and is told.
The operating instructions' troubleshooting table gives the same first remedy for a boiler that will not start — "building gas isolator cock closed: open the building-side gas isolator cock" — and that is the householder check: the lever on the gas pipe below the boiler, and whether other gas appliances light and a prepayment meter has credit.
Beyond that the causes are the gas supplier's or the engineer's. Low inlet pressure with the cock open and the meter working means a supply or regulator problem on the gas side, and low pressure with everything else normal can be a blocked filter under the Venturi cap, which the engineer will find while investigating the F.53 that often accompanies it. The Energy, Ultimate, Easicom, Betacom and Compact tables have no F.54; on those boilers a gas supply problem shows as F.28 or F.29 alone. Nothing about this code says the boiler has a gas leak — it is short of gas, not losing it — but the usual rule holds: a smell of gas is a call to 0800 111 999 before anything else.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Gas isolator cock closed | Glow-worm's second cause and the first thing their operating instructions have the owner check. The lever on the gas pipe at the boiler, or the emergency control at the meter, has been turned off — by a plumber working elsewhere, or after a move. | Common |
| Prepayment meter out of credit or supply interrupted | "No or insufficient gas inlet pressure" from the supply side. Other gas appliances tell you: if the hob will not light either, the boiler is not the problem. | Common |
| Low inlet pressure with the supply present | A regulator or governor fault at the meter, an undersized or partly blocked gas pipe, or a filter under the Venturi cap that has become wet or blocked. The engineer measures inlet pressure at the boiler and works back. | Occasional |
What to try yourself
Check the gas isolator cock below the boiler is open — the lever in line with the pipe — and that the emergency control valve at the meter has not been turned off.
If you can smell gas, do not touch any switch; leave, and call 0800 111 999.Try another gas appliance. If a hob or fire will not light either, contact your gas supplier, and check a prepayment meter has credit.
With gas confirmed, press the reset button once. The 35 Store operating instructions allow three attempts before a competent person is called.
If F.54 returns with gas available everywhere else, stop resetting and book a Gas Safe registered engineer to measure the inlet pressure.
Get a Gas Safe registered engineer to look at your Glow-worm F.54
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£0–£200
Time on site
30 minutes
Nothing if the cock was closed or the meter empty. An engineer's visit to measure inlet pressure and clear a Venturi filter £80–£200; a supply-side fault is the gas network's to fix.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
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Glow-worm gas valve assembly
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Price checked 28 September 2026
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Related Glow-worm fault codes
- F.28Get it checkedThree ignition attempts have failed and the boiler has locked out. Glow-worm's guides let you check the gas supply and the condensate pipe and reset three times before calling anyone.Related: ignition and gas supply
- F1Get it checkedOn Ultracom, Flexicom and Ultrapower boilers F1 is an ignition lockout after five failed attempts, and Glow-worm's guides let you reset it. On Energy and Ultimate boilers F.01 is the return sensor instead.Related: ignition and gas supply
- F.29Get it checkedThe burner lit and then the flame went out while running. Glow-worm blame the gas supply, flue gas recirculating, earthing, the spark transformer and, on newer manuals, a blocked condensate pipe.Related: ignition and gas supply
- F.61Get it checkedThe board cannot drive the gas valve properly — a short in its wiring, coils shorted to earth, or the electronics. The valve stays shut until an engineer has traced it.Related: ignition and gas supply
- F.27Stop — call an engineerThe boiler is sensing a flame when there should not be one. Glow-worm list moisture on the electronics, a failed flame monitor or a leaking gas valve. Not a reset job.Related: ignition and gas supply
- F.68Get it checkedThe flame is burning but its signal is unstable. Glow-worm list air in the gas, low gas pressure, a wrong combustion setting or injector, a poor electrode connection or a blocked condensate pipe.Related: ignition and gas supply
Own a Glow-worm boiler? Save it and its codes come first next time.
Related guides
Common questions about Glow-worm F.54
Why do I see F.54 and F.28 together?
Glow-worm's own wording is "in combination with F.28/F.29". F.28 says ignition failed; F.54 says why — the board could not see enough gas pressure. Fix the gas and both clear.
My Energy7 shows F.28 with no F.54. Is that different?
Only in what the display can tell you. The Energy7 board does not measure gas flow, so it cannot separate no gas from any other ignition failure. The same checks apply.
Is this a leak?
No. The boiler is short of gas, not losing it. A smell of gas is a separate emergency handled by the National Gas Emergency Service, not by resetting.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.