If your boiler is old, noisy and needs repairing every winter, a straight swap for a new one is often quicker and cheaper in the long run than fixing it again — call 020 7183 4810 for a fixed price. Where the layout allows it, we can often complete a like-for-like combi swap in a single day across Pimlico, Gas Safe registered from start to finish.
Tired of repairing the same old boiler?
A straight swap can often be done in a single day, fixed price agreed upfront.
Need a Gas Safe engineer today?
Same day callouts across Central and West London, fixed quotes and fully guaranteed work.
A boiler swap keeps your existing pipework layout and simply replaces the appliance itself, which is why it’s usually the fastest way to fix an old, unreliable boiler for good. Here’s when it makes sense, and why it’s still a job for a registered engineer even though it’s the simplest type of replacement.
Signs your boiler needs swapping, not just repairing again
- It’s over 10–12 years old and this isn’t the first repair this year. At some point every further repair is money that would have gone towards a new, more efficient boiler.
- Your gas bills have crept up noticeably. Older boilers run at far lower efficiency than a modern A-rated combi.
- It’s getting louder — kettling, banging or rattling. That’s usually scale building up inside, and it tends to get worse, not better.
- Replacement parts are getting hard to source. Older discontinued models can mean longer waits and higher repair costs each time.
- You just want it done and out of the way. A straight swap is usually the quickest heating job we do.
Why a swap still needs a registered engineer, not a quick DIY job
| The shortcut | What actually goes wrong |
|---|---|
| “It’s the same boiler position, how hard can it be” | It’s still a gas appliance connection, and by law only a Gas Safe registered engineer may legally disconnect and connect one — doing it yourself is a criminal offence. |
| “Skip the flush, the old system was fine” | Years of sludge sitting in old radiators will flow straight into a brand-new boiler and is one of the most common reasons a manufacturer refuses a warranty claim. |
| “Reuse the old gas connection as-is” | A new, more efficient boiler can have different gas flow requirements. Skipping a pressure check risks ignition faults from the very first day. |
| “Just swap it myself over a weekend” | Beyond the legal issue, an incorrectly commissioned boiler won’t pass building control notification, and your home insurer can decline claims linked to unregistered gas work. |
Stop and call us rather than DIY-ing it if…
- You’re considering swapping the boiler yourself or using an unregistered fitter to save money
- Your current boiler is leaking, or has a cracked casing
- You’ve had more than two repair callouts in the last year
- You’re not sure if your existing gas pipework will suit a new boiler
What it costs to get it wrong
An unregistered or DIY swap can leave you with a boiler that isn’t legally connected, isn’t covered by a valid manufacturer warranty, and isn’t backed by your home insurance if anything goes wrong. Skipping the power flush is one of the most common reasons a new boiler underperforms or fails early. And repeatedly repairing an old boiler past the point of good value usually costs more over two or three years than a single, well-planned swap.
How Olia’s Plumbing & Heating handles it
- Survey and fixed quote. We confirm the swap is straightforward for your property and agree one price upfront.
- Protect your home. Floor protection down before any tools come out.
- Remove and replace. Old boiler safely disconnected and removed, new one fitted in the same position where possible.
- Flush and protect. Chemical power flush and magnetic filter fitted as standard.
- Test, certify and register. Combustion analysis, Gas Safe registration and manufacturer warranty registration before we leave.
- Gas Safe registered, Vaillant approved installer
- Often completed in a single day for a like-for-like swap
- Fixed price agreed before we start
- Manufacturer warranties of 7–12 years, properly registered
- Old boiler removed and recycled responsibly
Book your boiler swap today.
Fixed price, often done in a day, fully Gas Safe certified.
Frequently Asked Questions
Can a boiler swap really be done in one day?
Often, yes, if you’re replacing a combi with a combi in the same position. A full system swap that removes old tanks usually takes a bit longer. Call 020 7183 4810 and we’ll confirm after a quick survey.
How much could I save on gas bills with a new boiler?
It varies by property and current usage, but moving from an old, inefficient boiler to a modern A-rated model typically brings a meaningful reduction — we can talk through realistic numbers for your home during the survey.
Do I get a warranty on a swap the same as a full installation?
Yes — a straight swap still comes with the full manufacturer warranty (typically 7–12 years depending on the model), properly registered in your name.
What happens to my old boiler?
We remove it and take it away for responsible recycling, so there’s nothing left for you to deal with. Call 020 7183 4810 to book.
What if my situation is more complicated than a straight swap?
If you’re converting from a tank-and-cylinder system rather than a like-for-like swap, our Boiler Installation Pimlico team can advise on the best approach.
Book your boiler swap in Pimlico
Call 020 7183 4810 or request a call-back for a fixed-price quote.
Related services: Boiler Installation Pimlico · Boiler Repair Pimlico · Boiler Service London · Combination Boiler Installations Pimlico
Peyman
CEO & Founder — Gas Safe Registered Engineer
Peyman is the founder of Olia's Plumbing & Heating, a London based team with over 15 years of hands on experience in boiler installation and repair, central heating, gas work and emergency plumbing. He personally oversees jobs across Central and West London and writes these guides to help homeowners understand their heating systems.
- Gas Safe Registered
- 15+ years experience
- Covering all of London
