Boiler installation cost
by property size (1–4 bed)
If you’ve been Googling “how much is a boiler for a 1 bed flat?” and you’re getting those vague, copy-paste answers… yeah. Same. This page is the version we’d give a mate on the phone: realistic ranges, what actually changes the price, and the stuff installers don’t mention until they’re already in your kitchen.
Typical boiler install costs by property size
These ranges assume a normal London/East London style property and a standard Gas Safe install with commissioning, safety checks, paperwork. Not a “cash job in 2 hours” situation. (If someone’s quoting you that kind of thing, we should talk.)
| Property size | Common setup | Realistic fitted range |
|---|---|---|
| 1 bed flat | Combi swap, short flue run, minimal pipe changes | £2,000–£3,300 |
| 2 bed flat / maisonette | Combi swap or upgrade, a bit more pipework, possible flue constraints | £2,200–£3,700 |
| 2–3 bed house | Combi swap or system upgrade, longer runs, more rads/controls | £2,400–£4,300 |
| 3–4 bed house | Often system boiler (or higher output combi), hot water demand matters | £3,100–£5,200 |
| Conversions / tricky layouts | Flue reroutes, condensate issues, gas upgrade, access/scaffold, old pipework | £3,800–£7,500+ |
If you want the “bigger picture” version with examples and what makes quotes jump, this is our full pricing hub: the London boiler install cost guide.
How we price installs (and why we don’t do “mystery quotes”)
ARA Services is based out of Forest Gate (E7) — and most weeks we’re bouncing between Stratford, Ilford, Newham, Hackney, Tower Hamlets… you know how it is. Boilers are one of those jobs where people get burned (financially and emotionally), because they get quoted a number that’s basically a guess, and then the extras start landing.
We’ve been doing this long enough to know what usually trips installs up: flue locations, gas pipe sizing, condensate routing, the state of the system water, and whether the property is the sort where you can actually get a boiler into the cupboard without taking the door off.
Our Gas Safe engineer Abdul (Gas Safe no. 626557) is the one who’ll tell you, plainly, if your job sounds like a simple swap or if it’s heading into “we need to see this properly” territory. We’d rather lose a job than sell you a cheap number and then row back later.
If you’re comparing installers, this page shows our install approach end-to-end: how our boiler fitting process works. It’ll also help you spot red flags when someone’s pricing seems too good to be real.
The 7 things that change the quote (more than “1 bed vs 3 bed”)
I’ll keep this practical. When people ask “why is my mate’s install £2,400 and mine is £4,200?”, it’s usually one (or a mix) of the things below — not the brand name on the box.
1) Flue route & terminal position.
If the flue can go straight out the nearest external wall, lovely. If you’ve got restrictions, awkward angles, or it needs relocating,
the labour and materials climb quickly.
2) Gas pipe sizing (and how far the run is).
This one gets ignored in cheap quotes. If the existing gas feed is undersized for the new boiler, it needs upgrading — and that’s non-negotiable.
3) System condition (sludge, debris, old rads).
If the system water is dirty, you’re asking a new boiler to drink mud. Sometimes a flush is enough. Sometimes the truth is:
a couple rads are past saving.
4) Controls & compliance.
Proper controls, thermostats, TRVs — it’s boring until you see your bills. It also matters for compliance and commissioning.
5) Access.
Stairs, tiny cupboards, awkward loft hatches, parking, carrying kit through a building with no lift. It’s not glamorous — but it’s real cost.
6) Hot water demand.
A big family in a “2–3 bed” can need more hot water than a quiet “4 bed” with one bathroom. Bedrooms don’t always tell the truth.
7) Making it neat (and safe).
Some installs are “works, but looks like a mess”. We do tidy pipework, proper clips, safe clearances — the sort of job you’d be happy
to open the cupboard and show someone.
If you’re weighing combi vs system vs regular and you want the price implications explained properly (not sales talk), our master pricing page is here: full fitted boiler price breakdown.
Mid-page reality check (quick)
If you tell me “2 bed flat, combi swap” I can give you a sensible band in 60 seconds. If you tell me “2 bed flat, but the boiler is in a bedroom cupboard and the flue situation is weird”… then we’ll ask for photos. Either way, you’ll get a straight answer.
Call +44 7727 154746 or message us on WhatsApp. If you're in a cold flat and you just want to know what you’re in for, we get it.
Three installs that look “normal” on paper… until you’re there
I’m not going to pretend every job is a drama — most aren’t. But the *price swings* usually come from boring details that only show up when you’re standing in the property with a tape measure and a torch.
Example 1: 1-bed flat, “simple combi swap”.
Customer expected £2k because that’s what they saw online. When we arrived, the cupboard had almost no clearance,
and the condensate had been bodged into a waste pipe that wasn’t suitable. Not catastrophic — but not “plug and play” either.
It ended up as a clean install with proper routing and commissioning, not a rushed one.
Example 2: 3-bed terrace, boiler relocating.
The boiler worked fine where it was… but the layout didn’t. Relocation meant careful flue planning and making sure the gas feed was correct.
That’s where the cost moved — not because it was a “bigger house”, but because it was a different job entirely.
Example 3: 2-bed maisonette, access and building rules.
On paper: standard. In reality: restricted flue termination positions and awkward carry routes. No lift. Tight communal spaces.
Again — labour, access, compliance. That’s what you’re paying for.
If you’re currently “stuck choosing” between options, you’ll probably like this page too: combi boiler pricing explained without the fluff.
Not because we’re the cheapest — because the job lands properly
I’ll be honest: if you only want the lowest number, you can find it. London is full of it. The problem is what happens two weeks later when the boiler is short-cycling, the condensate freezes because it was routed badly, or your paperwork is missing when you need it.
People book ARA Services because we’re clear about the job scope and we do it cleanly: correct gas sizing, proper commissioning, safety checks, and we don’t vanish when you ring.
Also, we don’t talk down to you. If you’re comparing quotes, tell us what you’ve been offered. We’ll explain what’s included, what’s missing, and what questions to ask before you hand over a deposit.
Want to see the “big hub” this page feeds into? Here’s our main breakdown: new boiler fitted prices across London.
The stuff we hear again and again
We’re paraphrasing here (privacy), but this is genuinely the theme:
“They told me the price band before coming, then explained what changed it when they saw the flue situation. No pressure, just honest.”
“Clean install. No mess left behind. Paperwork done properly — and when I had a question two days later, they actually answered.”
“We had quotes all over the place. ARA were the only ones who explained gas pipe size and why the cheap quote didn’t make sense.”
Boiler costs by property size — quick answers
Is a boiler install always cheaper in a 1 bed flat?
Often, yes — but not automatically. If it’s a straightforward combi swap with an easy flue route and decent access, it’s usually the lowest band. But flats can be weird: restricted flue positions, tiny cupboards, awkward condensate routes, and building access rules. That’s why “1 bed” is a starting point, not a final price.
What’s the single most common reason quotes jump from £2,500 to £4,000?
Gas pipe sizing and system condition. If the gas run is undersized, it has to be corrected for safety and performance. If the system water is full of sludge, you either flush properly or you’re gambling with the new boiler’s lifespan.
Do I need a system boiler in a 4 bed house?
Not always. If the hot water demand is high (multiple bathrooms, busy mornings), a system boiler with a cylinder often makes sense. But some homes work perfectly with a high-output combi. We normally decide based on usage, pressure, and layout — not just bedroom count.
How fast can you give me a price range?
If it’s a basic description (“2 bed flat, existing combi, boiler on external wall”), we can give you a sensible band fast. If the layout is odd, we’ll ask for photos. Either way, you’ll get a realistic number, not a bait price. Call +44 7727 154746.
Is it worth paying more for a “better” boiler brand?
Sometimes — but the installation quality matters just as much. A premium boiler installed poorly is still a problem. We fit the major brands and we’ll tell you where paying extra makes sense (and where it’s mostly marketing).
Can you do a same-week install if mine’s on its last legs?
Usually, yes — depending on parts availability and whether it’s a simple swap or a conversion/relocation. If you’re stuck and it’s urgent, call us and we’ll be honest about timing.