Maybe it has come to the point where your old boiler has packed up, and the part you need is no longer available. Or perhaps you are pre-empting all those problems by changing your boiler before it gives up the ghost. Either way, knowing how much you should expect to pay for a new boiler is a bit tricky.
Why does one person get a new boiler for under £2,000 and another for £4,000? In this blog, we want to give you an idea of some of the costs involved, and what makes some jobs more expensive than others.
The boiler
Determining the cost of a boiler install is unfortunately not a simple business; it depends on a variety of different things. Firstly it depends on the size of the boiler you are installing – a small flat for example will require a much smaller boiler than a large house and the unit itself will be a few hundred pounds cheaper than a larger model of boiler.
>>> Can I get a grant for a free boiler? <<<
In addition it depends on what type of boiler you had originally and what type of boiler you are swapping to. On the whole there are two types of boiler – a regular boiler (with the hot water tank) and a combi boiler that makes hot water on demand (without a hot water tank). Approximate starting prices are discussed below:
- If you are keeping the same type of boiler (e.g. if you have a existing combi boiler you are replacing it with a new combi), the price to buy and install it will start at about £1300 provided there are no real plumbing adjustments required. As a guide, the price of installing a new boiler is approximately £600 – £1000 and then you will need to pay for the boiler on top of that.
- If you want to swap a regular boiler with a combi boiler unfortunately there will be a lot of pipework changes needed (although you will be doing away with your hot water tank!), so the price to buy and fit this type of boiler starts at about £1800.
All the prices listed above are starting prices – the final prices will be impacted by all the factors discussed below.
Gas pressure
Your heating engineer should always check the gas pressure going in to the boiler, because if this is insufficient, it could cause you problems. One of the issues that often comes up is where too narrow a pipe is used to take the gas from the mains at the meter to the boiler (usually to cut costs). If you have a narrow pipe coming out of your meter (15mm or less) you could have an extra cost on your hands.
Moving a boiler
Unfortunately, there are occasions when moving the position of the boiler will be necessary. If you have an old floor-mounted boiler, a back boiler, or simply a boiler in an unsuitable position (ideally boilers are now situated on external walls) the job will require significant rerouting of pipework and the further you have to move it, the more expensive the job.
Building regulations and flues
Over the years, legislation has changed dramatically, meaning a boiler installation 30 years ago will likely not meet current standards. If your flue is dispersing waste gas into a street for example, you may need a plume diverter to ensure people aren’t affected by the emissions. If your boiler is mounted in the centre of the house with the flue going up the chimney, this will no longer meet the regulations, and as such the boiler will need a new position on an external facing wall.
>>> What is the best brand of boiler to install? <<<
So you want your new boiler in exactly the same place – chances are you will be swapping an old conventional boiler with no condense pipe for a new condensing model, and as such, a condense pipe will need to run to a downpipe, sink or gutter. The difficulty involved here will also add to the cost of the job. You may even have an old asbestos flue, in which case you will need a specialist in to remove the material before the boiler can be installed.
Radiators and heating controls
Adding or replacing radiators and tanks will obviously make the job more expensive. Fortunately, it is not normally necessary to change them, and it is really easy to remove an old tank if you are switching to a combi. We would always recommend getting heating controls – which includes as a minimum a programmer and thermostat, but we would also suggest thermostatic valves on the radiators (known as TRVs) where the property is larger.
>>> British Gas – an Expensive way to get a new boiler! <<<
As an approximate guide, a programmer and thermostat will cost you a couple of hundred pounds, and each TRV for each radiator will cost about £50. If you have an outdated programmer or thermostat, or are lacking thermostatic radiator valves, it is really worth getting these replaced. They tend to pay back fairly quickly and don’t cost a lot of money.
Price varies dramatically with installer!
It is worth mentioning that although the workmanship of different installers does vary, as a bare minimum we recommend your choosen installer is Gas Safe – A Gas Safe registered engineer has been checked to make sure they are competent and qualified to work safely and legally with gas. This is the recognised installer mark of quality and has replaced the old ‘Corgi Registered’ mark.
>>> CHECK TO SEE IF YOUR INSTALLER IS GAS SAFE <<<
We too have seen the offers of £1000 installed boilers on Ebay and to be honest that is a little alarming!
Although all gas safe engineers will charge varying amounts for the work they do, our tip if you are looking for a value install is to use a small but highly recommended local installer. Also smaller companies may not be subject to sales VAT (if their revenue is less than £80k) and can therefore offer a few additional percent off the final price.
Having said that, we always recommend getting a quote from British Gas, to provide you with a high end quote so you can see that you are getting a good deal from a local installer!
How much will it cost to change your boiler?
I hope this gives you a better idea of some of the costs involved, and why changing a old floor mounted system boiler to a modern wall mounted combi might set you back £3,000, whereas switching a relatively modern boiler in the kitchen for a condenser might cost £2,000. Each property is different, but you should now have a bit of an idea what to expect when you get your quote.
Can I get a grant for a boiler replacement?
Installing a new boiler
Are you thinking about getting a new boiler? We have scoured the country for the best tradespeople, so that we can make sure we only recommend those we really trust.
If you would like us to find you a local installer to install a new boiler in your home, just fill in the form below and we will be in touch shortly!
How much would a biomass boiler set me back. I have seen Baxi do one but wondering how much extra the cost to install. And will any engineer be able to install it. Useful article though. Thanks.
It will cost about £10-11,000 (+ VAT @ 5%) for a biomass boiler to be installed. Remember you need to have a store for the fuel!!
I think the figures above are about right – we were going to install a new boiler using that Gov GDHIF scheme, but it seems that to be honest the cost of the extra bit of kit needed meant that it wasn’t worth it.
We have just been quoted £2435 + vat to swap our boiler out, taking our heat only boiler out + hot water tank and two cold water tanks in the loft and replacing it with a Baxi Duotec with 5 year warranty so we are going to go with it.
Dear Richard,
May I ask you which plumber you have found? Or how you have done your research?
I am thinking to change my boiler to a combi boiler.
Very good website… many thanks.
Hi Richard, We work with 10 or so boiler installers in London and that quote is pretty consistent. Try to push for a 7 year warranty if possible – if you would like us to help organise quotes and talk you through your options send us an email to mailbox@thegreenage.co.uk
Hi Richard, that is a pretty good price they have quoted to be honest – and the Duotecs are very good.
We used this to ‘quote ourselves’ then got British Gas out to quote. Their quote was almost double what we came up with! My advice, find a local gas safe engineer. They will install it for you as well as any British gas person and it will be a fraction of the price (or at least in line with your prices above!). Our Worcester combi + honeywell thermostat cost £2,300 including vat and it comes with a 5 year warranty so pretty happy to be honest. Useful info in this article though!
This is a great help! I assume you can get gas safe installers who aren’t VAT registered so you can save yourself a few hundred quid there on the cost of getting a new boiler installed. What about warranties? Do all boilers pretty much come with the same warranty?
How long will it take to install a new boiler? Need to know how long we will be without heating. Thanks
Hi Asha
If a boiler is being replaced with a similar boiler then the job will only take a couple of hours. If a new boiler is being installed and needs a flue through a wall and more pipework it should be done in two days.
My first boiler was installed by British Gas in 1970 and the flue installed, I think ,asbestos is treble insulated and painted. Never any problems.Boiler is floor standing and heating only. It is on first floor’s landing with flue going through ceiling, loft and roof. Can I keep my present flue ? Please, reply to my mail by return if possible. I wish to change my boiler now as my wife (80) and I (90) looking for peace of mind . Thank you in advance.
C.Kaminski
I just bought a flat with a boiler and tank. What roughly would be the cost to replace this with a combi condensing boiler? Anxious to get it done before the cold weather sets in!!
Hi Liam,
That depends on a lot of things, but for a combi swap you will probably be looking at somewhere in the region of £2,000 – 2,500 depending on the installer and the type of boiler you go for (if in doubt go Worcester Bosch or Vaillant and you won’t go too far wrong). When installing a new boiler the most important thing is to make sure the installer is gas safe – that seriously is the most important thing.
Good explanation,new Boiler cost depends on the product and usage of that product.Thanks for sharing such a great blog.
I AM LOOKING TO REPLACE MY GAS COMBI BOILER AND WILL BE GETTING QUOTES SHORTLY. I DONT THINK ANYTHING ELSE WILL BE REQUIRED – WHAT DO YOU THINK THE COSTS WILL BE ROUGHLY
Hi Russell, it depends on a few things – firstly the type of boiler you want to install. Secondly if the existing flue can be used (is your boiler currently on an external wall), also if they need to move the gas run at all (gas pipes used now are slightly wider than older pipes). Provided you go for a mid range boiler and the boiler can be sited in the same place and you don’t need to alter the gas run then the price of a new combi boiler is going to be approximately £1,600.
would like to replace power ax 155 to Worcester 30i combo boiler
I’m looking to install a new system boiler, to replace the one I have which is currently broke. I would like the system to be closed not open due to having a load of current issues with air locks in the system. I would like a new programmer and thermostat as the one I currently have is shocking. How much would this roughly cost? As I’m getting quotes this week. Much appriciated Rachael
Hi Rachael, are you replacing the tank as well? As this depends a little – whether you have a heat only boiler set up as a system boiler (with external expansion vessel) or you actually have a system boiler? The cost of the boiler will be approximately £1000 (for a decent brand, give or take a £100) and to install this will cost an additional £700 – £1500 depending where you are in the country.
Hi we had a Worcester boiler fitted about a year ago but now need to change it for a combi boiler as we are having substantial building work done including converting the loft. Is it possible to sell the boiler as it still has guarantee etc and if so where would we sell it? Many thanks.
Hi Helen, it is possible to buy second hand boilers (and therefore it is possible for you to sell yours!) however don’t expect to get too much. A quick Google search through up PreLoved – which looks like a fairly decent selling platform.
We live in a flat down near maidstone. Our combi boiler started leaking the other day, we called out an emergency plumber who put a sign on the boiler saying it was dangerous and turned it off. I have two questions, is this something you can fix. ie. replace a few parts and the boiler is as good as new. If not, and the boiler stays in the same position how much will it cost to get a new one? I am only going to be in the house for a couple more years, so don’t want to get the best, I just want to make sure it doesn’t break within 6 months. I assume they carry a few year warranty if I were to buy a new one to get me through till I leave.
We got a new boiler through greenage by one of their partner installers. It worked out very well. the new Valiant boiler came with a 7 year guarantee and the plumber who installed it was extremely friendly and also he cleaned as he went. Would strongly recommend getting greenage to get you a quote if you are looking for a new replacement boiler.
Very useful guide. Just bought a house and had no idea how much a boiler cost, but these numbers are spot on. Thanks for sharing!
Thanks SaUl, we still get lots of people sending us quotes to check and the difference between quotes is absolutely amazing. If an installer thinks they can get away with it by charging more they will unfortunately.
Very useful guide. Just had to get a new boiler and this was spot on. Thanks!
Hi Chris, we have been through the numbers and there hasn’t really been any change in boiler price over the last couple of years so these prices should still be pretty accurate!
I have back boiler. Can you replace these?
Our next house has warm air central heating. Can a replacement warm air unit be as small as a conventional gas boiler? If not what are the costs likely to be to replace the whole system?
I am interested in getting a new boiler, but having googled the price it looks like I can buy one for under £1000. Does it really cost £800 to install a boiler? I thought it only took one day to install?
Hi LTV111 a new boiler does cost about £1000 to buy, but there are lots of little extras that boiler engineers install that does impact the cost of the boiler. i.e. most boiler installers now install a Magnaclean as part of the install to help minimise build up of gunk in the boiler (which should improve the lifespan of the boiler). Likewise the cost of a new boiler also changes depending on where it is currently located – i.e. if the old boiler needs to be moved then this will really add to the cost. Prices will vary obviously depending where you are in the country and also from installer to installer depending on the margins they are looking to make on installing a new boiler, but on the whole the prices in the article offer a decent starting place on which you can compare quotes against.
Hi, I am interested in getting a new boiler in my flat, although we are on the 3rd floor and the flue goes out the wall in my kitchen. Can they puta new flue on the outside using a ladder or will it need scaffolding! Is there any rules you can force other tenants to help cover the cost of scaffolding works on the property if the works are required?
I have an old boiler in a flat,vented internally. If I fit a new combi,will I have to have it on an outside wall? (The only wall possible leads onto a balcony….) Can I use the internal vent and have a separate drain down to the bathroom? Three quotes so far, all insisting the new regs state it must be on an outside wall. 1958 building, internal concrete vent shared by two other flats.
I just got a new boiler in my house but need to move house now, any chance i could take it with me or is there no point ?