Below is our updated guide to hot water boiler prices. We have detailed how much it will cost to install a combi boiler, a heating only boiler, a system boiler and replacing a back boiler. We have broken boiler installation costs down into the price of the boiler and the total cost of the installation.
NEW! How much is a new hot water boiler? We’ve had lots of requests for stand alone boiler costs as part of this page. A new combi or system boiler will cost between £600 – £850 for a budget model, £800 – £1,100 for a mid range model and £900 – £2,000 for a premium model. Prices in each group vary according to boiler size. A heat only boiler will cost between £500 – £1,500 according to boiler size and quality. If you are looking for stand alone boiler prices you can also use our comprehensive guides: hot water boiler Prices; Heat Only Boiler Prices; System Boiler Prices. For a bespoke installation cost with suitable boilers from up to nine manufacturers try our Boiler Quote Calculator.
Hot Water Boiler Installation Costs
We have provided some estimated installation costs for four common scenarios (below).
- Regular (Heat Only) boiler installation
- Combination boiler installation
- System boiler installation
- 4) Back boiler replacement
For more on types of boiler (combi, heat only and system) try our Boiler Types Explained guide.
Costs include the boiler, labour, parts and VAT. We have assumed a mid–range boiler cost for a three bed house with a standard installation set up. Most companies now include a power flush at no extra cost when fitting a new boiler and our prices assume this has been included. To make sure you are getting a genuine, good quality power flush you can read our Guide to Power Flushing. Zozen there may be additional costs for example if:
- the gas pipe is undersized and needs to be re-run
- the system requires a condensate pipe for the first time
- the system needs to be sealed (i.e. there are currently expansion tanks in the loft)
- there are some building works, for example to brick up a large existing flue hole
How much does central heating cost to install? We also show you below costs for installing a full central heating system (new boiler + new radiators) in a 1 bedroom flat, 3 bedroom house and 5 bedroom house. For a more detailed breakdown on central heating costs with more property scenarios visit our Guide to Central Heating Costs.
1) Cost to install a Regular (heat only) boiler
Regular boilers are ‘heat only’ boilers. Very simply, the boiler will provide the heating and a cylinder will provide hot water.
The two scenarios below show rough costs for 1) replacing a regular boiler in its existing location and 2) a rough cost for installing a new regular boiler in a new location. The cost of a mid range heat only boiler in this scenario is £750.
The cost for moving the boiler will vary according to whether it will be in the same room or moved to another room. In both cases we have assumed the cylinder and all other existing equipment are left in place. To review heat only boiler prices by boiler brand read our Guide to Heat Only Boiler Prices
| Installation of a new heat only boiler | Approx cost with mid range boiler | Time taken |
|---|
1) Replacing an existing heat only boiler
with a new boiler, in the same location | £1,775 | 1 day |
2) Replacing an existing heat only boiler
with a new boiler, in a new location | £2,150 | 1.5 days |
2) Cost to install a Hot Water boiler
Combination boilers provide heating and hot water via the boiler (there is no cylinder). There are two main scenarios for combination boilers: A) The new combi boiler is replacing an existing combi boiler or B) the new combi boiler is replacing a regular boiler and hot water cylinder. The cost of a mid range heat only boiler in this scenario is £900.
To know if a combi boiler is suitable for your home, read our Guide to Combi Boilers. From more on pricing, read our Guide to Combi Boiler Prices, where we review the prices, efficiencies, warranties and hot water performance of 83 models of boiler from 9 boiler brands
A) Replacing an existing combi boiler
The two cost scenarios below show rough costs for a new combi boiler in the same location and for installing a new combi boiler in a new location. Again the cost for moving the boiler will vary according to where it is moved to.
| Installation of a new combi boiler | Approx cost with mid range boiler | Time taken |
|---|
1) Replacing an existing combi boiler
with a new boiler, in the same location | £1,995 | 1 day |
2) Replacing an existing combi boiler
with a new boiler, in a new location | £2,650 | 1.5 days |
B) Replacing a regular boiler and hot water cylinder with a combi boiler
In this scenario there are a lot of additional works to remove the hot water cylinder and re-direct the hot water pipes to the new combi boiler location.
| Conversion to a new combi boiler system | Approx cost with mid range boiler | Time taken |
|---|
1) Replacing an existing regular boiler and
hot water tank with a new combi boiler | £2,995 | 2.5 days |
3) Cost to install a System boiler
System boilers provide heating and work with an unvented hot water tank to provide hot water. System boilers are very high performing and are usually fitted in larger properties with multiple bathrooms.
It is unlikely that someone would wish to swap their existing system boiler and unvented hot water tank for a combi or heat only boiler, so we have concentrated on common scenarios and provided rough costs for 1) replacing a system boiler in its existing location 2) replacing a heat only boiler/vented cylinder with a system boiler/unvented hot water tank, 3) replacing a combi with a system boiler/unvented hot water tank (common for those extending their properties). In all cases we have assumed the boiler goes in the same location as the existing boiler. The cost of a mid range heat only boiler in this scenario is £850. For more on pricing, read our Guide to System Boiler Prices.
Type of boiler replacement – average figures.
Price will vary according to scope of works. | Approx cost with mid range boiler | Time taken |
|---|
1) Replacing a system boiler with a new system boiler
and retaining the unvented hot water tank | £1,900 | 1 day |
2) Replacing a heat only boiler and hot water tank
with a system boiler and unvented hot water tank | £4,000 | 2 days |
3) Replacing a combi boiler with a system boiler
and unvented hot water tank | £4,500 | 2.5 days |
4) Cost to replace a Back boiler
It is no longer possible to replace a back boiler with another back boiler, read our Guide to Back Boilers to find out more on repairing, maintenance and replacement.
We have provided two approximate costs for replacing a back boiler:
1) The back boiler is removed and replaced with a heat only boiler, but the hot water tank is retained.
2) The back boiler and hot water tank are removed and replaced with a combination boiler
Type of boiler replacement – average figures.
Price will vary according to scope of works. | Approx cost with mid range boiler | Time taken |
|---|
1) Replacing a back boiler with a new heat only boiler
and retaining the hot water tank | £2,750 | 2 days |
2) Replacing a back boiler and hot water tank
with a new combi boiler | £2,995 | 2.5 days |
3) Replacing existing back boiler with a new style boiler
and decorative fireplace | It is currently not possible to install a new back boiler | NA |
Central Heating Installation Cost
When fitting a ‘full heating system’ i.e. boiler plus radiators, costs will vary according to the size of the property. The table below gives and indication of central heating system costs for a 1 bedroom flat, 3 bedroom house and a 5 bedroom house. Costs include an appropriately sized combination boiler fitted in the kitchen with a standard flue kit, all gas and system pipework, standard manufacturer controls and radiators with thermostatic radiator valves. Read our Guide to Central Heating Costs for a more indepth review.
| Central Heating System Installation Scenario | Approx cost with mid range boiler | Time taken |
|---|
| 1) 1 bed flat | £3,500 | 2.5 days |
| 2) 3 bedroom house | £4,250 | 3 days |
| 3) 5 bedroom house | £5,500 | 4 days |
