Boiler Replacements – Major Factors That Add To Cost

08 May. 2019

Written by Neil Marsh MCIPHE RP RHP EngTech

Boiler Replacements – Major Factors That Add To Cost

Having a boiler replaced or a new boiler installed is hardly cheap. There are many aspects of a boiler installation that can add to costs. Below we discuss the more common causes what lead to the cost of a boiler installation increasing …

Gas Runs

Wherever possible, always try to utilise the existing gas supply to the boiler. The further the meter/property inlet is away from the boiler, and the more difficult the routing of the pipework, the more the boiler installation will cost. Also, keep in mind that running a gas pipe internally under floors can be disruptive to a home, as floor coverings will need to be lifted/removed, and floorboards would need to be cut to make access so that the required pipework can be installed. In some circumstances, there could be additional costs as a result of this, such as replacing a tiled or laminate floor.

Gas pipework can be run externally, depending on the circumstance this can reduce overall costs.

Flue Type & Length

Increased flue lengths and complications will add further costs to a boilers installation.

Vertical flues have more components and often cost more than their horizontal counterparts to install, especially where the flue exceeds one meter in length, or where access equipment is required. It is not uncommon for a vertical flue system to add £300-600.00 to the total cost of an installation in a small home, and this is excluding access equipment!

Other flue options, like plume kits and concealing exposed horizontal flue runs, can also add to costs.

Distance From Service Pipework

The further your boiler is from the central heating flow and return pipes and (if applicable) hot outlet and cold feed pipes, the more likely the boiler installation will cost due to increases in the amount of pipework and the time to do such work.

Control Replacement/Installation

If your central heating system has old controls, and/or is missing mandatory controls, new versions may be required. Traditional central heating systems, such as Y-Plan & S-Plan systems, generally have more controls, and any changes to them will add to the overall cost.

Access Equipment

If your boiler needs to be installed in a location where access equipment is required, costs will often increase sharply. Depending on your property, and the equipment being used, you may need to get permission locally to use the equipment.

Installing Boilers Into loft Spaces

Boilers installed in a lofts require that the loft is boarded for safe access, a fixed ladder is fitted to gain entrance into the loft and that a light is supplied. Should your loft fail to have any of these, there will be additional costs to make the space fit for the boiler to be installed.

Often additional work is involved fitting gas supplies, central heating pipes and (where applicable) hot and cold pipes into lofts. Even additional frost protection may be required.

Power Flushing

Although FORTHRIGHT quotes to undertake power flushing in Cheltenham, Gloucester and the other areas we install boilers as standard, many companies will charge for this as an expensive additional service when installing a boiler.

Some companies completely overcharge for a power flush and will charge as much as £800.00 for the power flushing of 10 radiators! Although Power flushing is not a mandatory requirement, FORTHRIGHT strongly advises not to install a boiler onto an existing system without doing so!

For information about power flushing, click here!

Manufacturers warranties are invalidated by sludge/scale/sediment. Contaminants within a central heating system shorten the lifespan of a boiler and its components. We strongly advise you to never skip on a correctly performed power flush, as in the long term, it will often save you money. Getting a company to do this correctly is a separate issue, so you should contact a company you can trust to do this correctly, like us. 

For information about common boiler and heating installation faults, click here.


If you are in need of a boiler replacement in Gloucester, Cheltenham, Stroud, Tewkesbury or any of the surrounding areas then contract FORTHRIGHT first! We install high quality boilers and systems at a fair price and always give our customers cost effective solutions. With no nonsense part and labour warranties of up to 10 years, you can’t go wrong with a boiler installed by FORTHRIGHT!