Whether the boiler is dead, locked out on a fault code, or leaving you with no heating or hot water, this page gets you to the right fix fast. Work through the safe checks below, find your symptom, and request a same-day callback before 2pm.
What should I do when my boiler stops working?
Work through five safe checks first: the pressure gauge (1.0–1.5 bar cold), the thermostat and timer settings, a single press of the reset button, the condensate pipe outside for ice in cold weather, and whether other gas appliances work. None of these involve opening the boiler casing — that is Gas Safe territory only. If the checks do not bring it back, a vetted Gas Safe registered partner engineer diagnoses the fault for a fixed £95, deducted in full from the repair.
Key points
Pressure gauge between 1.0 and 1.5 bar when cold
Thermostat calling for heat and timer on
One reset only — repeated resets can damage the gas valve
Condensate pipe outside checked for ice in winter
Never remove the boiler casing — Gas Safe engineers only
Find your symptom
No hot water but heating works — usually the diverter valve
No heating but hot water works — pump, valve or thermostat
Boiler keeps losing pressure — expansion vessel, PRV or a leak
Water under the boiler — switch off at the spur and call
Boiler dead in cold weather — check the condensate pipe for ice
Banging or kettling noises — sludge or scale in the heat exchanger
Check these first — safe homeowner checks only
Pressure gauge reads 1.0–1.5 bar cold (re-pressurise via the filling loop if low)
Thermostat has power, is paired, and is set above room temperature
Timer or programmer is calling for heat now
One press of the reset button after noting any fault code
White plastic condensate pipe outside checked for ice on freezing mornings
How the repair visit works
Fixed £95 diagnostic, booked to a two-hour window
Fault traced to the component — no speculative part-swapping
Written quote before any repair begins
Common Worcester, Vaillant, Ideal, Baxi and Glow-worm parts on the van
Check the fused spur switch next to the boiler, the consumer unit for a tripped breaker, and whether a power cut has reset the programmer. If the display is lit but dead otherwise, note any fault code and book the diagnostic.
Is it worth repairing an old boiler or should I replace it?
As a rule of thumb, if the repair would exceed roughly 40% of the £2,295 replacement cost, or the boiler is over 12 years old with a second failure in a year, replacement is the better value. Your engineer gives you both figures side by side before you decide.
How fast can someone come out?
Request a callback before 2pm and a partner engineer attends the same day across every EH postcode. After 2pm we book the next morning, and out-of-hours slots run after 6pm and at weekends at £140.
What does the fault code on my boiler mean?
Every brand uses its own codes — Worcester EA/E9, Vaillant F22/F28/F75, Ideal F1/L2, Baxi E119/E133. Our fault-code library explains each one and the likely repair before you book.