If your boiler has broken down, you’re probably asking one question: how much is this going to cost? In London, most boiler repairs cost between £80 and £350, depending on the fault, the time of day, and which part of the city you’re in. Simple jobs like resetting a fault code or replacing a valve sit at the lower end. Bigger problems, such as a faulty heat exchanger or PCB (printed circuit board), can push costs above £400.
This guide breaks down real London pricing by fault type, engineer hourly rates, call-out fees, and emergency repair costs, so you know what’s fair before you book anyone.
Average Boiler Repair Cost in London
Across London, homeowners typically pay the following for common boiler repairs. These figures reflect standard weekday rates from Gas Safe registered engineers and don’t include VAT unless stated.
| Repair Type | Average Cost (London) | Typical Time |
|---|---|---|
| Diagnostic visit / call-out only | £60 – £100 | 30–60 mins |
| Reset / minor fault fix | £80 – £150 | 30–90 mins |
| Replace a valve or thermostat | £120 – £220 | 1–2 hours |
| Fix a leak (pipe or seal) | £100 – £250 | 1–3 hours |
| Replace a pump | £150 – £280 | 1–2 hours |
| Replace a PCB (circuit board) | £200 – £450 | 1–3 hours |
| Replace a heat exchanger | £350 – £650 | 2–4 hours |
| Full boiler service | £70 – £120 | 45–60 mins |
Prices vary between boiler brands and models. Parts for premium brands like Worcester Bosch or Viessmann tend to cost more than budget models, and older boilers sometimes need parts sourced specially, which adds time and cost.
Boiler Engineer Hourly Rate in London
Most London boiler engineers charge £50 to £90 per hour, with many quoting a fixed price for the first hour that includes the call-out. Independent local engineers are usually cheaper than large national heating companies, while engineers working for big brands (British Gas, HomeServe) often charge £90–£120 an hour due to overheads and branded servicing plans.
- Independent local engineer: £50–£75/hour
- National heating company: £80–£120/hour
- Out-of-hours or weekend rate: £90–£150/hour
Some engineers charge a flat “first hour” rate that covers travel and diagnosis, then bill in 30-minute increments after that. Always ask whether the quoted rate includes VAT and parts, or whether those are added separately.
Boiler Repair Call-Out Fee in London
A standard call-out fee in London ranges from £40 to £90, usually covering the engineer’s travel and the first part of the diagnosis. Some companies waive this fee if you go ahead with the repair; others charge it regardless of whether work is carried out.
Things that affect the call-out fee:
- Time of booking – same-day and evening call-outs cost more than a booking made a few days ahead.
- Location within London – Zone 1 and central boroughs sometimes carry a small travel premium.
- Company type – large national providers often bundle the call-out into a higher hourly rate rather than charging it separately.
Emergency Boiler Repair Cost in London
Emergency boiler repair costs in London typically run £100 to £300 for evening, weekend, or bank holiday call-outs — roughly 30–50% more than a standard weekday appointment. A no-heating, no-hot-water emergency in winter is treated as urgent by most engineers and usually gets same-day attention.
| Timing | Typical Emergency Repair Cost |
|---|---|
| Weekday evening (after 6pm) | £120 – £220 |
| Weekend | £150 – £280 |
| Bank holiday | £180 – £320 |
| Overnight | £200 – £350+ |
If your boiler is leaking gas, showing signs of carbon monoxide (a stale smell, soot marks, or a pilot light burning orange instead of blue), turn it off, ventilate the property, and contact the National Gas Emergency Service on 0800 111 999 immediately. This is a safety issue, not just a repair cost question.
Cost by Common Boiler Fault
Search intent around boiler repair usually starts with a specific symptom. Here’s what each one typically costs to fix in London.
Boiler Not Heating: Repair Cost
A boiler that isn’t heating usually costs £100 to £280 to fix. Common causes include a faulty thermostat, diverter valve, or airlock in the system. If the issue is a broken heat exchanger, costs can rise to £350–£650, and at that point many engineers will recommend comparing repair cost against replacement.
Boiler Losing Pressure: Repair Cost
Fixing a boiler that keeps losing pressure typically costs £80 to £200. This is often caused by a small leak in a pipe or valve, or a faulty pressure relief valve. In many cases, an engineer can top up the pressure and identify the leak source in a single visit.
Boiler Leaking Water: Repair Cost
Leaks usually cost £100 to £250 to repair, depending on whether the source is a seal, pipe joint, or internal component. If the leak has caused damage to a PCB, the cost can climb toward £400–£450 because the board needs replacing.
Boiler Making Noise: Repair Cost
Banging, gurgling, or whistling noises (often called “kettling”) typically cost £90 to £200 to fix. This is commonly caused by limescale buildup or trapped air, and sometimes requires a power flush, which is priced separately (usually £300–£600 for a full system flush).
Boiler Keeps Turning Off: Repair Cost
This fault typically costs £100 to £250 to diagnose and fix. Causes range from a low water pressure sensor fault to a blocked condensate pipe (common in cold weather) or a failing thermostat.
Boiler Error Code: Repair Cost
Fixing a boiler showing an error code costs £80 to £300, depending on what the code points to. Some codes indicate a simple reset is needed; others point to component failure. Keep your model number and the exact code ready when you call an engineer — it speeds up diagnosis and can lower the visit cost.
Combi Boiler Repair Cost vs Other Types
Combi boilers are the most common type in London homes, and repair costs are broadly similar across boiler types, though combi boilers have more components (like the diverter valve) that can fail.
| Boiler Type | Typical Repair Cost Range |
|---|---|
| Combi boiler | £80 – £450 |
| System boiler | £90 – £450 |
| Conventional (regular) boiler | £90 – £500 |
| Back boiler (older systems) | £150 – £600+ |
Back boilers and older conventional systems often cost more to repair because parts are harder to source and take longer to fit.
Boiler Replacement vs Repair Cost
Not every fault is worth fixing. A widely used rule of thumb in the heating industry is the “£1 per year” guide: if the repair cost in pounds is higher than your boiler’s age in years multiplied by roughly £30–£50, replacement is usually the better financial decision.
| Factor | Repair Makes Sense | Replacement Makes Sense |
|---|---|---|
| Boiler age | Under 8 years old | Over 10–12 years old |
| Repair cost | Under £300 | Over £400–£500 |
| Fault frequency | First or second fault | Repeated faults (3+ in 2 years) |
| Efficiency | Still rated A-rated (90%+) | Older G-rated, inefficient models |
| Parts availability | Common, in-stock parts | Discontinued or hard-to-source parts |
A new combi boiler installation in London typically costs £2,000–£3,500 including labour, which is why engineers usually only recommend replacement once repair costs start approaching a third of that figure, or the boiler has a track record of repeated breakdowns.
What Affects Boiler Repair Costs in London
Several factors push London prices above the national average, which typically sits around 10–15% lower than inner London rates.
- Location – Central London and inner boroughs generally cost more than outer London due to higher engineer overheads and travel time.
- Time of call-out – Evenings, weekends, and winter peak season (November–February) carry higher rates due to demand.
- Boiler brand and age – Premium brands and older or discontinued models often need specially sourced parts.
- Access and property type – Flats with restricted access or shared boiler cupboards can add time to a job.
- Warranty status – A boiler still under manufacturer warranty may qualify for free parts, with only labour charged (or nothing, if under a service plan).
Boiler Repair Prices by London Area
Pricing differs slightly across London depending on local demand and travel distances.
- North London boiler repair: Similar to the citywide average, with slightly higher demand in winter months due to older Victorian housing stock in areas like Islington and Haringey.
- South London boiler repair: Generally close to average pricing, with independent local engineers offering competitive rates in outer boroughs like Croydon and Bromley.
- East London boiler repair: Prices trend slightly lower in outer east boroughs, though inner east areas near the City can carry a small premium.
- West London boiler repair: Tends to sit at the higher end of the range, particularly in central and southwest boroughs, reflecting higher living and business costs.
If you’re comparing “boiler repair near me” quotes, get at least two or three from local, Gas Safe registered engineers rather than relying on the first search result — prices for the same job can vary by £50–£100 between companies in the same postcode.
How to Reduce Your Boiler Repair Costs
- Book an annual service. A £70–£120 yearly service often catches small faults before they become expensive repairs.
- Don’t wait for a full breakdown. Odd noises or pressure drops are cheaper to fix early than after the boiler stops entirely.
- Check your warranty first. Many boilers under 5–10 years old still have manufacturer cover for parts.
- Compare fixed-price quotes. Ask for a fixed price rather than an open-ended hourly rate where possible.
- Consider a boiler cover plan. Monthly cover plans (typically £15–£30/month) can offset repair costs if your boiler is older and prone to faults.
- Bleed radiators and check pressure yourself. Some “faults” are simple fixes you can do without calling an engineer at all.
How to Find a Trustworthy Boiler Engineer in London
Always confirm an engineer is Gas Safe registered before they touch your boiler — this is a legal requirement in the UK for anyone working on gas appliances. You can check any engineer’s registration number for free on the Gas Safe Register website.
Look for:
- A valid Gas Safe ID card (ask to see it, or check the register online)
- Clear, itemised quotes before work begins
- Reviews on independent platforms, not just the company’s own site
- A written guarantee on parts and labour (typically 12 months minimum)
Frequently Asked Questions
How much does boiler repair cost in London on average?
Most boiler repairs in London cost between £80 and £350, depending on the fault. Simple fixes sit near the lower end; component replacements like a PCB or heat exchanger cost more.
How much does an emergency boiler repair cost?
Emergency call-outs in London typically cost £100 to £300, roughly 30–50% more than a standard weekday visit, with the highest prices on overnight and bank holiday call-outs.
What is the average boiler engineer hourly rate in London?
London boiler engineers usually charge £50 to £90 per hour, though national companies can charge £80–£120 per hour including overheads.
How much does it cost to fix a leaking boiler?
Fixing a leak typically costs £100 to £250, depending on whether the source is a seal, valve, or pipe joint, and whether any components were damaged by the leak.
How much does it cost to fix a boiler that isn’t heating?
This usually costs £100 to £280. Common causes include a faulty thermostat or diverter valve; if a heat exchanger needs replacing, costs can reach £350–£650.
Is it cheaper to repair or replace an old boiler?
If your boiler is under 8 years old and the repair is under £300, repair is usually the better value. For boilers over 10 years old with repair costs above £400–£500, replacement (around £2,000–£3,500 installed) is often more cost-effective long term.
Do I have to pay a call-out fee even if I don’t go ahead with the repair?
It depends on the company. Some London engineers waive the call-out fee if you proceed with the repair; others charge it regardless of the outcome. Always confirm this before booking.
How much does a boiler service cost in London?
An annual boiler service typically costs £70 to £120 and is one of the most effective ways to prevent costly breakdowns.
Why is London boiler repair more expensive than the national average?
London rates run about 10–15% above the UK average, driven by higher engineer overheads, travel time in traffic, and stronger demand, particularly in central and southwest boroughs.
How do I know if my boiler engineer is legitimate?
Check that they’re Gas Safe registered — this is a legal requirement for anyone working on gas boilers in the UK. You can verify any engineer’s ID number for free on the Gas Safe Register website before they start work.
Final Thoughts
Boiler repair costs in London depend heavily on the fault, the timing, and who you call — but knowing the typical price ranges above means you won’t be caught off guard by a quote. For most common faults, expect to pay somewhere between £80 and £350, with emergency and out-of-hours call-outs sitting higher.
Before booking, get a written quote, confirm the engineer is Gas Safe registered, and ask whether the price includes parts and VAT. If your boiler is older and this isn’t its first breakdown, it’s worth asking your engineer for an honest opinion on repair versus replacement — a straight answer now can save you money over the next few winters.