Do you have an old system and want to know what's involved when installing a new boiler? We have you covered in this guide.
Want to replace your older boiler?
Whether you want to know what this process involves, how much it costs, or how long the work takes, you’ve come to the right place.
In this boiler replacement guide, we’ll answer the above questions and explore other related topics.
We’ll start off with perhaps the most important issue when it comes to a boiler replacement, especially in the current climate, that being the price tag.
PS we fit new boilers with gas installation nationwide. Simply answer these questions, get your fixed price and you could get it installed as quick as tomorrow.
Cost of Fitting a New Boiler to an Old System
With supply and labour costs taken into account, the cost of replacing an older boiler with a new one will almost always cost several thousand pounds.
Please be aware that all cost ranges featured in this section are estimates and some jobs could have price tags outside the ranges given below.
There are two broad categories of boiler replacements: like-for-like and conversion.
The former means that you are having your boiler replaced with the same type (e.g., a combi boiler replacing an existing combi boiler) whereas a boiler conversion involves switching type (e.g., replacing a regular boiler with a system boiler).
Without further ado, here are some estimated boiler replacement price ranges…
Replace a Regular Boiler with:
Combi Boiler - £2,500 to £4,000.
System Boiler - £2,500 to £4,500.
Regular Boiler - £2,500 to £4,500.
Replace a Combi Boiler with:
Combi Boiler - £1,250 to £3,650.
System Boiler - £1,250 to £4,150.
Regular Boiler - £1,250 to £4,150.
Replace a System Boiler with:
Combi Boiler - £1,250 to £3,650.
System Boiler - £1,250 to £4,150.
Regular Boiler - £1,250 to £4,150.
If you want to have a biomass boiler installed, you’re probably looking at paying over £10,000 and perhaps even close to £18,000 for the most expensive options.
Curious to know what the best boiler brands are on the market? Check out our popular guide of the ten best boiler brands to buy from in 2024.
Cost-affecting Factors of a Boiler Replacement
The figures given in the previous section are, as mentioned, just estimated price ranges. Let’s look at the factors that shape these price estimates.
Cost Factors of Replacing a Boiler include:
Size and type of existing boiler being removed.
Size and type of new boiler being installed.
Whether you are changing the system.
Whether you intend to have your boiler relocated.
Ease of access.
State of the work area.
The region of the UK you live in*
If scaffolding is needed^
*As for where you are based, this is relevant because labour costs differ throughout the UK. Prices tend to be lower in northern England, Scotland, and Northern Ireland. On the other hand, they are usually above average in southeast England. London is notorious for its high prices.
^It is rare that scaffolding would be required. However, if the flue is difficult or/and unsafe for a heating engineer to reach even with a ladder, they’ll need to use scaffolding.
We’ll touch on some of these price factors in a little more detail shortly.
What Does Replacing an Old System with a New Boiler Involve?
We’ll now break down the various steps that are generally involved in replacing an old system with a new boiler.
Please be aware that these steps must be completed by a Gas Safe registered engineer and are not suited for a DIY enthusiast.
Broadly speaking, here is how an old system is replaced with a new boiler:
The existing central heating system (CHS) is powered off and the power isolated at the mains
The old boiler and fittings are removed
The new boiler is installed including the pipework
If applicable, a new water storage tank will be added (e.g., a combi boiler being replaced with a system boiler would require a new separate water storage tank, mostly likely in the loft)
All relevant connections and remaining work are complete and checked to ensure everything is good
The power is turned back on before the new CHS is powered up
The new CHS is tested
If everything is good, it is now safe to use
Any necessary clean up can now be undertaken (some of the clean-up will take place during the previous steps) and the old CHS can be disposed of
Where do you get rid of an old boiler/CHS?...
In most cases, the engineer themselves will be able to get rid of the old boiler.
Otherwise, contact your local council prior to having it removed by a professional for guidance. A boiler and central heating components must be disposed of properly.
Note: You may also wish to have your central heating system flushed as part of the replacement work.
We’ll now look a little more at the different potential aspects of a boiler replacement…
Do You Need to Change System?
The exact process of fitting a new boiler to an old system will depend on the boiler type being removed and the type being installed in its place.
A like-for-like replacement would be simpler than having a brand-new system fitted (e.g., converting a regular boiler to a combi boiler).
Changing a boiler system involves extra work elements such as:
Removing the cylinder.
Modifying the pipework.
Upgrading your boiler controls.
One important note when it comes to replacing a boiler is that it really only makes sense to have a new regular boiler installed as a like-for-like replacement since regular boilers feature complex pipework as a more traditional option.
Relocating Your Boiler
Another aspect of a boiler replacement that may apply is relocating a boiler. Should you wish to have it relocated, this will add to your bill and extend how long the work takes.
You may, for instance, wish to have the new boiler fitted in a different room for practical or even visual purposes. Relocating the placement of your home’s boiler would involve the pipework being redirected.
Boiler Replacement Work Duration
The time it takes for a boiler to be replaced will, just like the price tag, depend on a variety of factors.
Across the board, it takes around one to three days to replace an old boiler with a new one. It should take no more than five days.
Time Factors of Replacing a Boiler:
Size and type of existing boiler being removed.
Size and type of new boiler being installed.
Whether you are changing system.
Whether you intend to have your boiler relocated.
Ease of access.
State of the work area.
If scaffolding is needed
Looking for a great deal on a new boiler?
If so, get your boiler replacement installed with Heatable. Here’s why:
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Thousands of happy customers – an average score of 4.9 on Trustpilot (that’s better than the market leader).
Price match guarantee – if you find a cheaper quote, we will match (must be like for like)
Multiple payment options - interest-free available
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Fixed price guarantee – no hidden costs
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