Glow-worm boiler repair
Energy, Betacom and Ultimate repairs and replacements. £99 fixed diagnostic inc VAT across Birmingham, the Black Country and the wider West Midlands — and a straight answer on whether yours is worth repairing.
Common faults
What goes wrong with Glow-worm boilers
F1 — ignition lockout
No flame detected. Gas, electrodes or a blocked condensate pipe.
F22 — low water pressure
Needs repressurising. Repeated loss means a leak or a failed expansion vessel.
F75 — pressure sensor / pump
No pressure change detected on firing. Common on Energy models; usually the sensor or vessel.
F28 — failed to ignite
Repeated ignition attempts failed. Gas valve, electrode or condensate.
Cold water in the shower
Diverter valve sticking or a scaled plate heat exchanger — very common.
Pricing
What a repair costs
Fixed diagnostic callout
Includes the first 30 minutes on site
£99
Typical parts and labour
Sensors, electrodes, valves, pumps — quoted before we start
£120 – £380
Major components
Fan, gas valve or PCB — we'll price replacement alongside
£350 – £550
New Worcester or Viessmann boiler fitted
Replacements are Worcester Bosch Greenstar or Viessmann Vitodens, both with up to a 12-year manufacturer guarantee registered in your name.
from £1,795
Straight talk
Is your Glow-worm worth repairing?
Glow-worms are cheap to repair thanks to the shared Vaillant parts bin. Under ten years old, repair. Older Micron, Hideaway and Ultracom units are usually better replaced.
Fault codes
Glow-worm fault codes we see most
Low pressure
Pressure below 1 bar — heating won't run properly
Not an emergency, but a system losing pressure weekly is leaking somewhere. Get it found before it damages floors or ceilings.
Frozen condensate
Boiler locked out after a cold night
Often a DIY fix. If it refreezes every cold snap, get the pipework corrected properly.
Symptoms
Or start with what it's doing
Boiler losing pressure
A sealed heating system should hold roughly 1 to 1.5 bar cold. If yours keeps sliding towards zero, water is escaping somewhere — pressure does not simply evaporate.
Boiler leaking water
A leaking boiler is never something to leave. Water and electrics in the same casing means the PCB is on borrowed time, and a slow leak will rot the heat exchanger from the outside in.
No hot water
When the heating works but the taps run cold, the boiler is firing — it just is not sending the heat to the right place. That narrows the fault down to a handful of components.
Boiler keeps turning off
A boiler that lights and then shuts down within a minute or two is protecting itself. Something in the safety chain — flow, flame, pressure or airflow — is not happy.
Radiators cold at the bottom
Cold at the top and hot at the bottom means trapped air — bleed it. Cold at the bottom and hot at the top means magnetite sludge sitting in the radiator, and bleeding will do nothing at all.
Boiler making a banging noise
Boilers make noise, but they should not make new noise. A change in sound is nearly always the first warning that something is scaling, sticking or starving of flow.
Book it
Get booked in today
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60 second boiler quote
No callbacks unless you want one
What can we help with?
Pick the option that fits — we'll tailor the next questions.
Frequently asked questions
Do you repair Glow-worm boilers?
Yes — all current ranges including Energy, Betacom and Ultimate. Parts are widely available so most repairs are first-visit fixes.
Are Glow-worm boilers any good?
They're a solid budget option owned by Vaillant, sharing many of the same components. Not as long-lived as a Worcester or Viessmann, but easy and cheap to maintain.
How much is a Glow-worm repair?
Usually £120–£300 inc VAT with a fixed price agreed before we start. The £99 diagnostic is refunded against the repair.