Emergency Plumbing & Boiler Repair · Mitcham, London
Boiler Installation & Replacement in Mitcham, London
When a boiler is past repairing, the choice becomes a replacement, and a quiet one is a rare luxury: most are decided on a freezing morning with no hot water. Emergency Plumber and Boiler Repair arranges boiler installation and replacement across Mitcham, and the partner heating company who attends will give a written quote for the new boiler, the flue, the controls and the clean-up before anything is ordered.
In London a new combi boiler typically costs between £2,800 and £4,800 fitted, according to published 2026 guides, while a like-for-like swap of a small combi runs lower and a larger system with a new cylinder runs higher. The honest answer to "how much" depends on the boiler's output, the type, the flue route and what else must change, which is why the partner looks before quoting.
Three choices decide most installations. A combi heats water on demand with no tank, ideal for smaller homes with one or two bathrooms. A system boiler feeds a hot-water cylinder, better where several taps run together. A regular boiler with a loft tank suits older homes with low mains pressure. The partner will recommend one after asking about your household, your existing pipework and your water pressure.
A new boiler is built to Building Regulations Part L, which sets efficiency and requires a condensing boiler with suitable controls such as a programmer and room thermostat, and where an unvented cylinder is fitted, Part G covers the safety devices. Gas work follows the Gas Safety (Installation and Use) Regulations 1998 and the manufacturer's installation instructions, and a new installation is notified to building control, which for Mitcham is Merton Council at the Civic Centre in Morden.
Local homes affect the job. The 1930s semis built on former farmland around Pollards Hill, the Victorian terraces nearer Figge's Marsh and the 1960s estates each give an installer a different flue route and pipework layout, and in the Cricket Green Conservation Area, designated in 1995, a flue on a street-facing wall needs thought. Call 07897 016796 and tell us what you have.
What We Do
Combi, System or Regular: Choosing the Boiler for the House
The partner will recommend one, but it helps to arrive at the conversation knowing the differences.
Combi Boilers for Smaller Homes and Flats
A combi heats water as you use it, so there is no tank, no cylinder and more space, which suits Mitcham flats and smaller terraces. It needs decent mains pressure and can struggle if two showers run together. Typical London all-in prices run from about £2,800 up to £4,800 depending on output and flue.
System Boilers and Unvented Cylinders
A system boiler heats a stored cylinder and can supply several bathrooms at once, and with an unvented cylinder the water arrives at mains pressure. Part G covers the safety devices on unvented cylinders, so this route has more to inspect, and the quote will include the cylinder, pipework and discharge route.
Regular Boilers and Keeping an Existing Loft Tank
Where an older house has a loft tank, a cylinder and low mains pressure, a modern regular boiler can replace the old one without altering the whole system. Where the system is dirty, a cleanse should come first, as set out on our power flushing page, or the new boiler inherits the old sludge.
The Benefits
What Is Included in a Boiler Replacement Quote
Ask the partner to itemise these in the written quote so you can compare like with like.
The Boiler, the Flue and the Controls
The quote should name the boiler make, model and output, the flue and terminal, and the controls such as a thermostat or smart control. Part L expects a minimum level of controls, and the right controls often matter as much as the boiler for running costs.
Filter, Cleanse and Commissioning
A magnetic filter, system cleanse and inhibitor protect the new boiler from old sludge and, on Mitcham's hard supply, from scale. The engineer should commission the boiler, test the flue and explain the controls before leaving.
Removal, Making Good and Paperwork
Taking out the old boiler, capping redundant pipework and making good where the flue passes through a wall belong in the quote, along with the manufacturer's warranty paperwork and the building control notification.
Why Us
Why a Replacement Is Matched to a Partner, Not Just Priced
A boiler swap goes wrong when it is sold on price alone, so we match on the job.
Right Specialist for Your Boiler Type
A combi in a flat, a system boiler with an unvented cylinder and a regular-boiler replacement call for different experience. We pass the details to the partner best suited.
Written Quote Before Anything Is Ordered
You see the quote in writing, with the partner company's name, before any boiler is ordered. The partner invoices and takes payment directly, and we take no money.
One Number if the Install Needs Following Up
If something is not right after the installation, ring 07897 016796 and we chase it with the partner. The terms of service page sets out where responsibility sits.
Questions Worth Asking Before You Accept a Boiler Quote
A quote that lists only a price and a boiler name leaves too much unsaid. These are the points that separate one quote from another.
- What output and which model? A flat with one bathroom and a four-bedroom house need very different outputs, and an oversized boiler cycles on and off and wastes fuel.
- Where does the flue go, and what does it look like from outside? Flue terminals have minimum distances from windows and boundaries, and in a conservation area the position may need the council's view.
- What controls come with it? Part L expects a minimum standard, and a smart or weather-compensating control can matter as much as the boiler for running costs.
- Is a system cleanse and filter included? Without one, a new boiler inherits the old circuit's sludge and, on a hard supply, its scale.
- What happens to the old boiler, and who tells building control? Removal and the notification to Merton or Wandsworth belong in the quote, not on your to-do list.
Timing a Replacement So You Are Not Without Heat
Planned Replacement
A planned swap in the warmer months lets you compare quotes, choose a date and avoid the rush when boilers fail in the first cold snap. Most like-for-like replacements take a day, and a change of boiler type or a new cylinder can take longer.
Emergency Replacement
When a boiler fails beyond repair in winter, the partner can often quote for a replacement at the same visit, though stock, the type of boiler and the flue route all affect how quickly a new one can be fitted. Ask what temporary heating or hot water they can arrange while you wait.
Landlords and Letting Properties
If you rent the property out, tell us when you ring, because the partner can combine the installation with the paperwork that goes with a new gas appliance and agree access with your tenant.
Not sure a replacement is needed? Start from boiler repair costs or a boiler service. The full list is on our services page.
Frequently Asked Questions
How much does a new boiler cost in London?
Published 2026 guides show a combi boiler installed in London typically costing £2,800 to £4,800, with the spread driven by output, brand, flue route and extras such as a smart control or magnetic filter. A system boiler with a new cylinder costs more, and a straight like-for-like swap costs less. The partner company's written quote is the only figure that counts, and it should itemise everything.
Should I choose a combi, system or regular boiler?
A combi suits smaller homes with one or two bathrooms and decent mains pressure, because it heats water on demand with no tank. A system boiler with a cylinder suits larger households that run several taps at once. A regular boiler keeps an existing loft tank and cylinder, which suits older homes with low pressure. The partner will recommend one after asking about your household, pipework and pressure.
What Building Regulations apply to a new boiler?
Part L sets efficiency requirements and expects a condensing boiler with controls, usually a programmer and room thermostat, and often a weather or load compensation for larger systems. Part G covers hot water safety, including unvented cylinders. The installation is notified to building control, which for Mitcham, Colliers Wood and Morden is Merton Council at the Civic Centre in Morden, and for Tooting is Wandsworth Council.
How long does a boiler replacement take?
A like-for-like combi swap typically takes a day, and a change of boiler type, a new flue route or a new cylinder can take two or more. Heating and hot water are off while the old boiler is out, so ask the partner about timing and whether a temporary solution is available. They will give you a realistic window in the written quote and tell you what could extend it.
Do I need to flush the system when I replace the boiler?
Usually, yes, or at least a cleanse. Old heating circuits hold magnetite sludge that damages new boilers, and many manufacturers' warranty conditions ask for the system to be cleansed to BS 7593 and a magnetic filter fitted. On a hard-water supply like Mitcham's, scale protection matters too. The partner will say whether a power flush or a lighter cleanse suits your system, and our power flushing page explains the options.
Can the flue go on the front of my house?
It depends on the building. In a conservation area, such as Mitcham's Cricket Green Conservation Area designated in 1995, or the Totterdown Fields estate in Tooting, a flue on a street-facing wall may need checking with the council. Flue terminals also have minimum distances from windows, boundaries and each other. The partner will survey the route and tell you what is possible before quoting.
Is it worth repairing instead of replacing?
It can be. A boiler under ten years old with a single failed part is often worth repairing, while one past fifteen years with parts discontinued or a cracked heat exchanger rarely is. Ask the partner for the repair price and the replacement price side by side. Our boiler repair page explains the usual faults and what repair typically costs.
What warranty will I get with a new boiler?
Warranty length depends on the manufacturer and model, and many require the boiler to be installed by a suitable engineer, commissioned correctly and serviced yearly. Ask the partner which warranty applies, what it covers and what paperwork you will receive, and keep the commissioning record and service history. We do not promise a particular warranty, because the terms are the manufacturer's and the partner's.
Can you arrange a replacement in an emergency?
Yes, we can arrange a partner to attend an emergency, assess whether the boiler can be repaired and quote in writing for a replacement. Stock, the type of boiler and the flue route all affect how quickly a new one can be fitted, and in a hard frost the merchants and partners are stretched. Ask the partner what temporary heating can be arranged while you wait.
Who installs the boiler, and who do I pay?
An independently owned partner heating company installs the boiler, quotes in writing before work, invoices you and takes payment directly. We do not take payment or send invoices, and we text you the partner's name before they arrive. If something is not right after the install, ring 07897 016796 and we chase it. See how we match a partner.
Boiler Beyond Repair? Get a Written Quote
Call 07897 016796 any hour and we will arrange the nearest partner heating company for Mitcham.
07897 016796