Combi boiler
Heats water on demand, straight from the mains. No hot water cylinder, no tanks in the loft.
Best for: Flats and most 1 to 3 bedroom homes with one bathroom, or two with a larger model.
Read more →Gas Safe registered · Croydon & South London
Boiler installation in Croydon
New combi, system and regular boilers fitted by Gas Safe engineers who work in Croydon every day. Tell us about your home in two minutes and get a fixed price, usually without anyone needing to visit first.
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Prefer to talk? Call 020 3856 8293
- About 2 minutes
- No obligation
- Used only for your quote
Fixed written price
- Gas Safe No. 567789Check us on the register
- Fixed written quoteThe price you agree is the price
- City & Guilds certifiedTrained and qualified
- Fully insuredPublic liability cover
What we do
Everything for your boiler, done properly
New boilers are what we do most. When yours needs fixing or checking, it’s the same engineers.
01Combi boilers
Hot water on demand and no tanks. Sized to your bathrooms and mains flow.
Find out more
02Boiler replacement
Old, unreliable or broken down. Like-for-like swaps usually done in a day.
Find out more- 03
Combi conversions
Lose the cylinder and loft tanks, or finally replace that back boiler.
Find out more 
04Boiler repair
Lockouts, leaks, low pressure and fault codes on all the major makes.
Find out more
05Servicing
Annual services and landlord gas safety certificates, with flue gas analysis.
Find out more
06Radiators and power flushing
Cold spots, sludge and noisy pipes sorted, and the system protected.
Find out more
New boilers, done properly
A new boiler is a big decision. We keep it simple.
Most people only buy a boiler two or three times in their life, usually when the old one has just given up. That is a bad moment to be comparing brands, kilowatts and flue kits. So our quote form asks the questions an engineer would ask on a survey, and a Gas Safe engineer looks at your answers and comes back to you with a price and a recommendation.
We fit gas boilers for homes all over the borough: flats near East Croydon, Victorian terraces in Thornton Heath and South Norwood, 1930s semis in Purley, Coulsdon and Shirley, and larger family homes in Sanderstead and Selsdon. Every installation is carried out by On Track Plumbing & Heating Ltd, Gas Safe registered under number 567789.
Not sure what you need? That's normal. Pick “Not sure” wherever it comes up and we'll work it out from the photos, or read our guides to combi boilers, converting to a combi and what a new boiler costs.
What good looks like
Anatomy of a proper boiler installation
Eight things that separate an installation that lasts from one that doesn’t. Whoever you choose, check your quote covers all of them.
- 1
The right boiler, properly sized
Chosen for your hot water demand and the home’s heat loss, with mains pressure and flow measured on the survey. Not just the biggest one on the van.
- 2
A new flue, in a legal position
Flue terminals must sit clear of windows, doors, boundaries and eaves. A new flue kit goes in with every boiler.
- 3
Magnetic system filter
Catches the rust and sludge that circulate in older systems before they reach the boiler’s heat exchanger.
- 4
Gas supply sized for the boiler
Combis can need more gas than the boiler they replace. The pipe from the meter is checked and upgraded if it’s too small.
- 5
Condensate drain that won’t freeze
Routed inside to a drain where possible. Outside runs are kept short, insulated and wide enough not to block in a frost.
- 6
Controls that meet Boiler Plus
Time and temperature control as a minimum, and on a combi an extra energy-saving measure such as a smart thermostat with optimisation.
- 7
System cleaned and protected
Radiators and pipes flushed, then dosed with inhibitor to slow new corrosion. Required by the regulations and by every manufacturer.
- 8
Commissioned and signed off
Gas pressure and combustion checked with an analyser, the Benchmark checklist completed, Building Control notified and the warranty registered.
Which boiler?
Combi, system, regular or back boiler?
The four kinds of gas boiler you’ll find in Croydon homes. The pictures show how each one is piped, which is why the swap from one to another takes longer.
System boiler
Heats a hot water cylinder, usually in an airing cupboard. Mains-fed, so no loft tanks.
Best for: Bigger homes with two or more bathrooms in use at the same time.
Read more →Regular boiler
Also called heat-only or conventional. A cylinder plus cold water tanks in the loft.
Best for: Older homes with low mains pressure, or where the pipework is built around it.
Read more →Back boiler
Sits behind a gas fire in the chimney breast. No longer made, and parts are hard to find.
Best for: Nobody, now. Replacing one is a common job in Croydon’s 1930s semis.
Read more →How it works
From quote to warm house
No pushy home visit, no hard sell.
- 1
Tell us about your boiler
Two minutes in the quote form: what you have, where it is, how big your home is. Add a photo of the boiler and the flue if you can.
- 2
Get a fixed price
A Gas Safe engineer reviews it and calls you with a written quote and a recommendation. If anything needs checking, we pop round first.
- 3
Installation day
We protect the floors, take the old boiler out, fit and commission the new one, clean the system and show you the controls.
- 4
Paperwork sorted
We register the warranty with the manufacturer and notify Building Control through the Gas Safe Register. Your certificate arrives by post.
Comparing quotes
What your quote should include
Use this to compare any two quotes. If one is cheaper, check it isn’t simply missing something on this list.
A proper installation includesWhy it mattersAsk on any quote
A survey of flue, gas supply and water flow
Decides the boiler size and whether a combi will give decent showers.
“How did you size the boiler?”
System cleaned to BS 7593, with inhibitor
Sludge from the old system is the main killer of new boilers.
“Is a full system clean included?”
Magnetic system filter
Keeps catching debris for the life of the boiler.
“Which filter, and where will it go?”
Controls that meet Boiler Plus
A legal requirement in England, and it saves gas.
“Which controls are included?”
New flue kit, positioned to the rules
Reusing an old flue or a bad position can fail inspection.
“Is the flue new, and where will it exit?”
Condensate pipe protected from frost
A frozen condensate pipe is the most common winter breakdown.
“Where will the condensate drain?”
Old boiler, tanks and cylinder removed
Disposal costs money. Make sure it’s not an extra on the day.
“Is removal and disposal included?”
Building Control notified, warranty registered
Without them, selling the house and claiming on the warranty get harder.
“Who notifies, and who registers the warranty?”
Installation day
What happens on installation day
A like-for-like replacement is usually done in a day. Conversions and moving the boiler add a day or two, and we’ll tell you the plan in advance.
- 01 · Arrival
Dust sheets down, water and gas off
We protect floors and the route to the boiler, then isolate the gas, water and power.
- 02 · Morning
Old boiler out
The old boiler is drained and removed. If tanks or a cylinder are going too, they come out now.
- 03 · Midday
System cleaned
The radiators and pipes are flushed so the new boiler starts on clean water.
- 04 · Afternoon
New boiler, flue and filter in
The new boiler goes up with its flue, filter, condensate drain and controls, and the pipework is tidied.
- 05 · Commissioning
Tested and set up
Gas tightness and combustion are checked with an analyser, inhibitor is added and the flow temperature set for efficiency.
- 06 · Before we leave
Shown how it works
A walk-through of the boiler and controls, the Benchmark checklist handed over, and the warranty and Building Control paperwork underway.
Who you’re dealing with
Don’t take our word for it. Check us.
Anyone working on gas in your home must be on the Gas Safe Register. It takes thirty seconds to check, and you should check whoever you use.
- 1Go to the Gas Safe Register’s “Find an engineer” page.
- 2Enter our registration number, 567789.
- 3On the day, ask to see the engineer’s Gas Safe ID card. The back lists the work they’re qualified to do.
Gas Safe registered
Registration number 567789. Required by law for anyone working on gas appliances.
City & Guilds certified
Formally trained and qualified in plumbing and heating.
Fully insured
Public liability cover for work in your home.
On Track Plumbing & Heating Ltd
A registered limited company, not a one-off trader. Your quote and paperwork come from the company.
Sizing guide
What size boiler do I need?
A rough guide for Croydon homes. Bigger isn't better: an oversized boiler cycles on and off and wastes gas. We confirm the size by checking your water pressure and flow rate on the day of the survey.
| Home | Bathrooms | Usually suits | Output |
|---|---|---|---|
| Flat or 1 to 2 bed house | 1 bathroom | Combi | Around 24 to 28kW |
| 3 bed house | 1 bathroom | Combi | Around 28 to 32kW |
| 3 to 4 bed house | 1 bathroom + en-suite | Larger combi | Around 32 to 38kW, if mains flow allows |
| 4 bed or more | 2+ bathrooms used at once | System boiler + cylinder | Sized to the home’s heat loss |
Repair or replace?
Signs it’s time for a new boiler
A good engineer will tell you when a repair is the better option. These are the signs that it usually isn’t.
It’s over 12 to 15 years old
Parts get harder to find and each repair buys less time. Older boilers are also far less efficient than a modern condensing boiler.
It keeps breaking down
If you’ve had two or three call-outs in a year, the money is usually better spent on a replacement with a fresh warranty.
Your gas bills keep rising
A boiler that has lost efficiency burns more gas for the same heat. Controls like a smart thermostat help too.
Yellow flame or soot marks
A healthy flame is blue. A lazy yellow flame or black marks round the case can mean carbon monoxide. Turn it off and get it checked.
You still have a back boiler
They’re no longer made and are the most common “can’t get the part” repair we see. Converting frees up the chimney breast too.
Your home has changed
A new en-suite or loft conversion can outgrow an old combi. We size the replacement for how you live now.
Before you choose anyone
Six questions to ask any boiler installer
Including us. A good installer will be glad you asked.
- 01
“Can I see your Gas Safe ID card?”
Check the card is current and covers gas boilers. It’s on the back.
- 02
“How have you sized the boiler?”
A good answer mentions your bathrooms, hot water use and water flow, not just bedrooms.
- 03
“Is the price fixed, and what isn’t included?”
You want a written price that lists the work, not an estimate that grows on the day.
- 04
“Will you clean the system first?”
Fitting a new boiler to dirty water shortens its life and can affect the warranty.
- 05
“Who registers the warranty and notifies Building Control?”
Both should be done for you, in your name.
- 06
“What happens if something goes wrong after you leave?”
Know who to call, and how the warranty works with the installer.
Areas we cover
Boiler engineers across Croydon
We’re based in South London and work right across the borough and the roads just over its borders.
- Croydon town centreCR0
- AddiscombeCR0
- ShirleyCR0
- WaddonCR0
- New AddingtonCR0
- South CroydonCR2
- SandersteadCR2
- SelsdonCR2
- CoulsdonCR5
- Old CoulsdonCR5
- PurleyCR8
- KenleyCR8
- Thornton HeathCR7
- NorburySW16
- South NorwoodSE25
- Upper NorwoodSE19
- SelhurstSE25
- Broad GreenCR0
- MitchamCR4
- WhyteleafeCR3
- WallingtonSM6
- BeckenhamBR3
Postcodes: CR0, CR2, CR3, CR4, CR5, CR7, CR8, SE19, SE25, SW16, SM6, BR3. Not sure if you’re covered? See the full list or just put your postcode in the quote form.
Guides
Read before you decide
- Choosing a boilerCombi vs system vs regular boiler: which is right for your home?Combi, system or regular boiler? How each one works, which homes each suits, and when changing type makes sense. A plain guide from Gas Safe engineers.Read the guide
- Choosing a boilerWhat size boiler do I need?What size boiler do you need? How kW, mains flow rate, bathrooms and heat loss decide it, why bigger isn’t better, and the rough sizes for flats and houses.Read the guide
- Choosing a boilerQuestions to ask a boiler installerThe questions to ask any boiler installer before you book, what good answers sound like, and how to check an engineer’s Gas Safe ID card and registration.Read the guide
FAQ
Boiler installation questions
How long does a boiler installation take?
Swapping a combi for a new combi in the same place is usually a one-day job. Moving the boiler, or converting a system or regular boiler to a combi, usually takes two days and occasionally three if there are tanks to remove from the loft.
Do I need to be at home?
Someone needs to let us in at the start, and we like to show you how to use the new boiler and controls at the end. You don’t need to be there all day.
Will I be without heating and hot water?
Only on the day of the work. The water and gas are turned off while the old boiler comes out and the new one goes in, then everything is back on before we leave.
Can I still have a new gas boiler?
Yes. There is no ban on replacing a gas boiler in an existing home. The rules that restrict fossil fuel heating apply to newly built homes, not to replacing the boiler you already have.
What paperwork will I get?
A completed Benchmark checklist for the boiler, the manufacturer’s warranty registered in your name, and a Building Regulations Compliance Certificate, which the Gas Safe Register sends to you after we notify them of the installation. Keep them together: you’ll need them if you sell the house.
Do you install boilers in flats?
Yes, including flats above the first floor. Flats often have the boiler in a kitchen cupboard with a flue through the outside wall. If your building has a managing agent or freeholder, check whether they need to approve a new flue position.
Can you install a boiler my landlord has asked me to arrange?
We can, but we’ll need the landlord or letting agent to confirm the go-ahead, because the boiler belongs to them. Tick “Tenant” in the quote form and we’ll take it from there.
Everything we do
New boilers
Conversions
Repairs & servicing
Get a fixed price for your boiler
Answer a few quick questions, add a photo if you can, and a Gas Safe engineer will come back to you with a price.