Typical timeframes
- 4–8 hours: straightforward combi swap (same location)
- 1 full day: most like-for-like boiler replacements
- 1–2 days: upgrades that include cleaning/protection + controls
- 2+ days: relocations, cylinders, tricky flue/condensate routes
How long does a boiler installation take?
Real timelines (not “it depends”)
If you’re asking this, you’re probably not casually browsing. It’s usually: “I’ve got no heat, I’ve got work tomorrow, and I don’t want my kitchen turned into a building site for a week.” Totally fair.
We’re ARA Services Ltd — Gas Safe engineers based in Forest Gate (E7), out and about daily across North & East London. If you want us to tell you the likely timeline for your setup, call +44 7727 154 746. Phone first. No finance plans. Just a clear answer.
Same-day swaps
2-day upgrades
Relocations & cylinders
Quick answer: most installs are 1 day… but here’s the honest split
If it’s a like-for-like swap in the same location with decent access, it’s often done in a day. The jobs that creep into day two are usually the ones with a “hidden” complication: moving the boiler, sorting a tired system, changing flue/condensate routes, or upgrading controls properly.
Best way to get an accurate answer
If you send photos (boiler + pipework around it + controls + any cylinder/tank), we can usually tell you the likely timescale before anyone books a survey.
Use: our contact page or call +44 7727 154 746.
If you want to see what “done properly” includes (commissioning, safety checks, registration etc.), this is the main hub: our boiler installation process.
TL;DR — what decides whether it’s a 1-day job or a 2-day job
This is the exact stuff we check when someone asks “how long will we be without heating?” (Because that’s the real question.)
It’s usually same-day if…
- Boiler is staying in the same place
- Access is decent (not wedged behind washing machines / tight boxing)
- Flue route is straightforward and compliant
- System isn’t heavily sludged
- Controls are simple (or already decent)
If you’re also comparing costs alongside timings, this keeps it grounded: new boiler cost & installation guide.
It often becomes 2 days if…
- We’re relocating the boiler (new pipe runs, new flue plan)
- A cylinder is involved (system boiler setup)
- The system needs a proper clean + protection
- Old valves/pipework need sorting to avoid future problems
- We’re upgrading controls properly (not just “wired in and left”)
Want real examples of swaps vs more complex changes? boiler change price examples in London.
Fastest way to avoid surprises
A lot of “it took longer than expected” stories start with a quote that didn’t include the awkward bits. If you want a clean checklist that avoids back-and-forth, use: what we need for an accurate quote (quick).
A real London example: the “one-day install” that nearly wasn’t
We had a job near Stratford where the customer was told it was a simple same-day swap. On paper, it was: combi in the kitchen cupboard, flue out the wall, job done. The only thing is… the cupboard had been “improved” over the years. Boxing-in everywhere, isolation valves that didn’t isolate, and pipework you could tell had been nudged a dozen times.
We still finished the same day, but only because we planned properly and didn’t pretend everything would be perfect. If we’d rushed it to hit a headline timeline, that boiler would’ve been the one taking the blame later. This is why we’d rather be honest up front than optimistic and stressed half-way through.
If you’re still deciding whether you need a replacement at all, start here first: boiler repairs and straight advice. Sometimes it’s genuinely repairable.
What actually happens during an install (so the time makes sense)
People imagine it’s just “old off, new on”. The timeline makes more sense once you see the steps. (And yes, we do the paperwork properly. It matters for warranties and safety.)
Morning: protection + strip-out
Dust sheets down, water isolated, system drained safely, old boiler removed. If access is tight, this alone can add time — not because we’re slow, but because we’re not smashing cupboards to bits.
Midday: install + pipework + flue/condensate
New boiler mounted, pipework made neat and serviceable, flue route checked and fitted correctly, condensate routed sensibly (and protected where freezing is a risk).
If you’re comparing quote differences, you’ll see why here: why new boiler prices vary so much.
Afternoon: cleaning, commissioning, setup
System gets cleaned/treated as needed, magnetic filter checked/installed if part of the plan, boiler commissioned, gas pressures checked, controls set up properly, radiators balanced where required. Then we walk you through it so you’re not guessing later.
End of day: handover + tidy + paperwork
We clean up, remove waste, and make sure you’re actually comfortable using the controls. Boiler installs shouldn’t end with “good luck”.
Want the full install standard we work to? boiler installation done properly.
Want a realistic timeline for your exact home?
Call +44 7727 154 746 and tell us where the boiler is now, how many bathrooms you’ve got, and whether you’re keeping it in the same spot. If you’re stuck near Forest Gate station / Romford Road and you need it handled quickly, say so — we’ll tell you what’s realistic.
Call — get a straight timeline
Prefer not to talk right now? Send photos here: message your setup.
Three common scenarios (and the timelines we usually see)
These aren’t “perfect world” examples. They’re the ones we see in London all the time. Not identical, but close enough to help you plan your day.
1) Like-for-like combi swap (same spot)
Usually: 1 day. If access is decent and the system isn’t wrecked, you’ll typically have heat and hot water back the same day.
If you’re collecting quotes, these examples help you compare properly: what “boiler fitted” usually includes.
2) Upgrade + system cleaning/protection
Usually: 1–2 days. If the system water is filthy, rads are cold at the bottom, or the old boiler’s been limping, cleaning takes time. Done right, it protects the new boiler and stops the “new boiler, same old problems” situation.
3) Boiler relocation / cylinder work
Usually: 2+ days. New routes, new pipe runs, flue planning, sometimes carpentry access, sometimes building rules if it’s a flat. It’s not scary — just needs proper planning.
What customers mention afterwards (timing + cleanliness)
People remember two things: did it get sorted quickly, and did the house look like a tornado hit it. Timing matters — but so does doing it properly.
“My boiler went wrong… Abdul and his team came and fitted a new one. They worked without taking a break, cleaned up when…”
Alison Louis“Great service prompt and efficient. Fitted a new boiler… took away old boiler and all other waste…”
Grant Hodges (Local Guide)“I called Abdul Monday, he sorted my new boiler and shower Saturday… explained everything…”
Anoushka Shaw (Local Guide)If your boiler’s already dead and you’re trying to plan around work, school runs, or tenants, call +44 7727 154 746 and we’ll tell you what’s realistic.
FAQ (timelines, disruption, and the stuff people worry about)
Can a boiler replacement be done in one day?
Yes — most like-for-like swaps in the same location can be done in a day, especially if access is decent and no major pipework or route changes are needed. The jobs that spill into day two are usually relocations, cylinder work, or installs where the system needs proper cleaning and protection.
Will I be without hot water and heating the whole time?
During the work, yes — because the system is drained and isolated. But on many one-day swaps, you’ll have heating and hot water back the same day. If it’s a bigger job, we’ll tell you upfront so you can plan (especially if you’ve got kids or tenants).
What usually makes an install take longer than expected?
Hidden access issues, isolation valves that don’t isolate, unexpected pipework problems, tricky flue/condensate routes, and systems that are heavily contaminated. That’s why we ask for photos and details first — it stops the “surprise” moment. If you want the fast checklist we use, it’s here: how to get an accurate quote quickly.
Do you need to do a power flush for it to be a one-day job?
Not always. Some systems only need a chemical clean and inhibitor top-up with protection. But if the system is badly sludged, cleaning can add time — and skipping it can cause problems later. If you want a realistic cost picture that includes these “extras”, use: new boiler cost & installation ranges.
Is it faster if I buy the boiler myself?
Sometimes it feels like it should be, but the time is usually in the installation steps — not the purchase. If the boiler turns out to be unsuitable, that can slow everything down. If you’re already choosing between brands, this is the honest comparison: Worcester vs Vaillant vs Ideal.
How can I get a timeline without booking a survey?
Send photos of the boiler area (including pipework), controls, and any cylinder/tank (if you have one), plus a note on bathrooms. Use our contact form and we’ll reply with the likely timescale. Or call +44 7727 154 746.