Fixed prices · Gas Safe registered
Boiler Repair in South London
No heating or hot water is never just an inconvenience - in January it's an emergency. InstaGasWorks is a Gas Safe registered engineer repairing boilers across South London, with same-day diagnostics, honest advice and fixed written quotes before any work starts.
The diagnostic visit is £120, and if you go ahead with the repair quote the fee is deducted from the bill. All the major brands are covered - Vaillant, Worcester Bosch, Ideal, Baxi and more - and you'll always be told plainly when a repair no longer makes financial sense.
Boiler Repair prices
Boiler / system breakdown call-out
£120
What the diagnostic visit covers:
- Full diagnosis of the fault
- Written repair quote before any work
- Fee deducted if you accept the quote
- All major brands - Vaillant, Worcester, Ideal, Baxi
Emergency gas leak call-out
£180
- Immediate response, 24/7
- Gas supply made safe
- Leak traced and isolated
- Written quote for the repair
Radiator not heating / cold radiators
£60-£80
- TRVs checked
- Radiators bled
- System balanced
- Pump inspected
Controls & thermostats
£150
Install and upgrade heating controls and thermostats.
Parts are quoted before fitting - you'll never find a surprise on the invoice.
Before & after
Before
AfterFaults fixed every week
No heating or hot water
The classic winter call-out. Often a failed diverter valve, pump or PCB - diagnosed on site and quoted before anything is touched.
Losing pressure
A boiler that needs topping up every few days usually has a small leak or a tired expansion vessel. Left alone it only gets worse.
Fault codes on the display
Every brand speaks its own code language. Give the code when you call and your engineer will usually arrive knowing the likely culprit.
Leaks and drips
Water under the boiler is never normal. Catching a perished seal early is a cheap fix; ignoring it can kill a heat exchanger.
Banging and gurgling
Kettling noises usually mean scale or sludge in the system - common in South London's hard water. Sometimes the real fix is a powerflush.
Frozen condensate pipe
The cold-snap special. The pipe is thawed, then re-routed or insulated so the same freeze doesn't stop your boiler next winter.
How a repair works
Step 1
Call with the symptoms
Describe what the boiler is doing and give any fault code on the display - it helps your engineer arrive with the right parts in the van.
Step 2
Same-day diagnostic
Your engineer finds the actual fault and explains it in plain English. The £120 diagnostic fee is deducted if you accept the repair quote.
Step 3
Fixed written quote
You approve the exact price before any work starts. If the boiler isn't worth repairing, you'll be told so and get a replacement quote instead.
Step 4
Repair and test
The fault is fixed, the system is run up to temperature and checked, and the engineer doesn't leave until the heating and hot water behave.
Boiler Repair questions, answered
How much does a boiler repair call-out cost?
The diagnostic visit is £120, and if you accept the repair quote that fee is deducted from the work - so the diagnosis effectively costs nothing when InstaGasWorks does the repair. Parts are quoted separately, in writing, before fitting.
Can you repair my boiler the same day?
Often, yes. Common parts for the major brands are kept on hand, and no-heat and no-hot-water calls get priority. If a part has to be ordered, you'll be told honestly how long it will take rather than left guessing.
Should I repair my boiler or replace it?
The honest rule of thumb: if a repair costs more than a third of a replacement and the boiler is over 10-12 years old, replacement usually wins. The £120 diagnostic gives you a clear picture, and the fee comes off the bill whichever route you choose.
Is it worth servicing a boiler that has just been repaired?
Usually, yes. A repair fixes the part that failed; a service checks everything around it and keeps your manufacturer warranty valid. If InstaGasWorks has just repaired your boiler, it can be serviced on the same visit, saving you the cost of a second trip - see the boiler service page for what each level covers and what it costs.
What should I do if I smell gas?
Don't wait for a repair appointment. Open windows and doors, don't touch electrical switches, and call the National Gas Emergency line free on 0800 111 999 straight away. Then call InstaGasWorks on 0208 226 0205 - emergency gas leak call-outs are £180, available around the clock.
More questions? Read the full FAQ or call for advice over the phone.
Related services: Boiler Service · Boiler Installation
Available across: Battersea · Putney · Balham · Tooting · Wandsworth · Clapham · Streatham · Wimbledon · Colliers Wood · Morden · Dulwich · Croydon · Thornton Heath · Norbury · Sutton · Mitcham · Carshalton · Wallington · All areas covered
Same-day availability
Speak to a Gas Safe engineer today
Fixed prices agreed before any work starts — book online with the card above, or talk it through first.