On this page
- What makes up the cost of a new boiler?
- Does the type and size of boiler matter?
- Why does moving the boiler cost more?
- What extra work does a new boiler often need?
- Why do installers give a fixed price only after a survey?
- How should you compare boiler quotes?
- Getting a fixed new boiler price in Stoke-on-Trent
- Frequently asked questions
Quick answer
The cost of a new boiler depends on more than the boiler itself. The main factors are boiler type and output, whether it stays in the same place, flue changes, cleaning the system, the controls needed to meet Boiler Plus, a magnetic filter, the condensate route and whether the gas pipe needs upsizing. A survey turns these into a fixed price.
Key takeaways
- The boiler is only part of the price; the installation work varies more.
- Moving a boiler or changing its flue route adds the most labour.
- Combis often need a larger gas supply pipe than old boilers had.
- Compare quotes line by line, not just on the total.
Ask three installers for a new boiler price and you may get three quite different figures for what looks like the same boiler. That is usually not because someone is overcharging. The boiler itself is only part of the job, and the work around it varies a lot from one house to the next.
What makes up the cost of a new boiler?
The price is made up of the boiler, the installation labour, the parts around it such as flue, filter and controls, and any work needed to bring the system up to current standards. A straight swap in the same position costs less than a job that moves the boiler, changes the flue or converts the system.
| Factor | Why it changes the price |
|---|---|
| Boiler type and output | Combi, system and regular boilers differ in price, and larger outputs cost more |
| Location | Moving the boiler means new gas, water, condensate and flue runs |
| Flue | A new route, vertical flue or plume kit adds parts and time |
| System condition | Sludge needs cleaning out before a new boiler goes on |
| Controls | Boiler Plus sets minimum controls for new installs in England |
| Gas supply pipe | An undersized pipe may need upgrading to feed the new boiler properly |
| Converting the system | Removing tanks and a cylinder for a combi is a bigger job |
Does the type and size of boiler matter?
Yes. Type sets the scope of the job and output affects the price of the boiler itself. A combi replacing a combi is usually the simplest install. Sizing should come from your home's hot water and heating demand, not the biggest number on the brochure.
For combis, the hot water flow rate is often what drives the choice, especially in homes with more than one bathroom. We explain this in combi boiler kW sizes explained. Choosing the right output avoids paying for capacity you will never use, or ending up with weak showers.
Why does moving the boiler cost more?
Moving the boiler means new pipework for gas, heating flow and return, cold mains and hot water, plus a new condensate route and flue. Each of those has to meet the manufacturer's instructions and current regulations, so relocation adds significant labour and materials compared with a like-for-like swap.
Flue positions are tightly controlled. The flue has to be a set distance from windows, doors, boundaries and other openings, so a spot that looks convenient may not be allowed. That is one of the things a survey checks before a price is fixed.
What extra work does a new boiler often need?
Most new boilers need a system clean, a magnetic filter, compliant controls and a suitable condensate route, and some need a larger gas pipe. These are not optional extras; they protect the new boiler and are often conditions of the manufacturer's guarantee.
- System clean. Old sludge left in radiators will damage a new heat exchanger. A chemical clean and flush, or a power flush on a badly contaminated system, is standard practice.
- Magnetic filter. Catches sludge before it reaches the boiler. See what a magnetic system filter does.
- Controls. Under Boiler Plus, new gas boilers in England need at least a timer and room thermostat, and combis need an extra energy-saving measure such as weather compensation or a smart thermostat with automation and optimisation. Our guide to Boiler Plus rules covers the detail.
- Condensate route. An outside run may need upsizing or rerouting to reduce the risk of freezing.
- Gas pipe upsizing. Combis can draw more gas than older boilers, and a supply pipe that was fine for the old boiler may be too small to maintain the pressure the new one needs.
Why do installers give a fixed price only after a survey?
Because most of the cost drivers can only be seen on site: the gas pipe size and route from the meter, the flue position, the state of the system water, the condensate route and the space available. A price given without that information is either an estimate that can change, or padded to cover unknowns.
A survey does not have to mean a home visit. We offer free remote video surveys over WhatsApp, FaceTime or Zoom, where you show the engineer the boiler, flue, gas meter and pipework on your phone. That is usually enough to give a fixed price, and a visit is arranged where it is not. You can start one through our free boiler quote page.
Before a video survey, clear the cupboard around the boiler and find where the gas meter is. The engineer will want to see the pipe leaving the meter, the flue outside and the pipes under the boiler.
How should you compare boiler quotes?
Compare quotes line by line rather than on the total. Check whether each one includes the same boiler model, system clean, filter, controls, flue, condensate work, gas pipe upgrade, removal of the old boiler and Building Regulations notification. A lower total often means something is missing.
Also compare the guarantee length and its conditions, and confirm the installer is on the Gas Safe Register. The installer should notify the work under Building Regulations, and you should receive a compliance certificate afterwards. Summer is a sensible time to replace a boiler, as you can do without heating for a day without any hardship.
Getting a fixed new boiler price in Stoke-on-Trent
Our new boiler packages are based on the Navien NCB300 combi in 28kW, 37kW and 41kW, each with a five year warranty, magnetic filter and wireless room thermostat. After a survey, you get a fixed price that shows what is included.
We install across Stoke-on-Trent, Staffordshire, south Cheshire and Derbyshire, from Stoke to Derby. To book a free video survey, call 07896 677083.
Frequently asked questions
Is it cheaper to replace a combi with a combi?
Usually, yes. A like-for-like combi swap in the same position reuses much of the existing pipework and often the flue route, so it tends to be the simplest installation. Costs rise if the flue, gas supply or condensate route needs changing, which the survey will identify.
Do I have to get a new radiator system with a new boiler?
Not normally. Existing radiators and pipework can usually stay, as long as the system is cleaned and in reasonable condition. Radiators that are badly corroded, leaking or undersized for the room may be worth replacing, and the engineer should point these out rather than include them by default.
How long does a new boiler installation take?
A straightforward combi swap is often completed in a day. Moving the boiler, converting from a regular or system boiler to a combi, or extensive pipework can take longer. Your installer should give you an expected timescale with the quote so you can plan around having no heating or hot water.
Does a new boiler need to be registered?
Yes, in two ways. The installer notifies the installation under Building Regulations, which leads to a compliance certificate being sent to you. Separately, most manufacturers ask for the boiler to be registered with them to activate the guarantee. Ask your installer which of these they handle for you.
Sources and further reading
Abdul runs Gasmaster Plumbing & Heating and has worked on boilers, heating and gas appliances across Stoke-on-Trent since 2005. He is Gas Safe registered (reg. 220932), and these articles come from his day to day work in homes and businesses across Staffordshire, Cheshire and Derbyshire.
