The type of boiler you choose will have a significant impact on the overall installation cost. Different boiler systems vary in price due to their design, efficiency, and installation requirements:

•Combi Boilers – These are the most popular choice for modern homes as they provide instant hot water without the need for a separate water tank. They are typically more affordable and easier to install.

•System Boilers – These require a hot water cylinder but no separate cold water tank, making them ideal for homes with higher hot water demands. Installation costs are slightly higher due to additional components.

•Conventional Boilers – Also known as regular or heat-only boilers, these require both a hot water cylinder and a cold water tank. They are more expensive to install, especially if switching from a combi system.

Boilers come in different sizes (measured in kilowatts, kW), and choosing the right size is essential to ensure efficient heating. The larger the boiler output, the more expensive the unit will be. Factors affecting the required boiler size include:

•The number of radiators in your home.

•The number of bathrooms requiring hot water simultaneously.

•Your home’s insulation and energy efficiency.

A small 24kW boiler may be sufficient for a small flat, whereas a larger home with multiple bathrooms may need a 35kW+ system, increasing both unit and installation costs.

Premium brands like Worcester Bosch come with higher upfront costs, but they also offer superior energy efficiency, reliability, and longer warranties. While cheaper boilers may seem like a cost-saving option, they often require more maintenance and have shorter lifespans.

The more complex the installation, the higher the labour costs. A straightforward replacement, where a new boiler is installed in the same location as the old one, will be more affordable. However, costs can rise if:

•The boiler needs to be relocated (e.g., moving from the kitchen to the loft).

•Pipework needs to be replaced or upgraded.

•Additional safety or compliance work is required.

Many homeowners choose to upgrade other aspects of their heating system alongside their boiler installation. These optional extras can increase costs but may improve efficiency and long-term savings:

•Smart Thermostats (e.g., Hive, Nest) – £150–£300

• Powerflush (system clean) – £300–£600

•New Radiators – £100–£300 per radiator

• Flue Extension or Repositioning – £100–£500

Labour costs vary based on the complexity of the installation and the experience of the engineer. In Glasgow, Gas Safe registered installers typically charge between £500 – £1,500 for installation, depending on the work involved.

Boiler installation costs can also be affected by where you live and the type of property you own. Homes with easier access to existing pipework and venting systems will have lower costs. If additional scaffolding or building work is required, such as in older tenement flats, this can increase the final price.