Your boiler accounts for around 60% of your home energy costs, making it the single biggest factor in your household energy bills. If your boiler is over 10 years old, it may be running at well below its original efficiency, costing you hundreds of pounds more each year than a modern replacement. With the UK government planning to phase out new gas boiler installations by 2035, now is a critical time to consider your options.
When to Replace Your Boiler
The average lifespan of a gas boiler is 10–15 years. Key signs that replacement is needed include frequent breakdowns, rising energy bills despite no change in usage, uneven heating across your home, and the need for increasingly expensive parts. If your boiler has an efficiency rating below A (90%+), replacing it with a modern condensing boiler could save you £200–£400 per year in gas costs alone.
Types of Boilers Available
Combi boilers are the most popular choice in UK homes, providing central heating and instant hot water without the need for a separate tank or cylinder. System boilers work with a hot water cylinder and are better suited to homes with multiple bathrooms. Regular (conventional) boilers require both a cylinder and a cold water storage tank, making them ideal for properties with older radiator systems. Hydrogen-ready boilers are a newer option designed to run on both natural gas and hydrogen, future-proofing your home for the potential hydrogen grid conversion.
Heat Pump Alternative
Air source heat pumps extract warmth from the outside air and use it to heat your home and hot water. They are significantly more energy-efficient than gas boilers, converting one unit of electricity into three or four units of heat. However, they work best with well-insulated homes and underfloor or oversized radiator systems. The Boiler Upgrade Scheme offers grants of £7,500 towards the cost of an air source heat pump, reducing the typical installed cost from £10,000–£15,000 to £2,500–£7,500.
Installation Costs
A new gas combi boiler costs £2,000–£4,000 installed. A system boiler with cylinder typically costs £2,500–£4,500. If you are switching boiler type (for example, from a regular boiler to a combi), expect to pay more for additional pipework. An air source heat pump costs £10,000–£15,000 before the government grant. Always obtain at least three quotes from Gas Safe registered engineers and check online reviews before committing.
The 2035 Gas Boiler Phase-Out
The UK government has announced that new-build homes will no longer be fitted with gas boilers from 2025, and all new boiler installations will move away from fossil fuels by 2035. This does not mean existing gas boilers will be banned, but it does mean that replacement options and government incentives will increasingly favour heat pumps and hydrogen-ready alternatives. Planning your next boiler purchase with this timeline in mind can save significant cost and disruption in the long run.
Key Takeaways
- A modern A-rated boiler can save £200–£400 per year compared to an older model.
- Combi boilers suit most UK homes; system boilers are better for multiple bathrooms.
- Air source heat pumps are eligible for a £7,500 government grant via the Boiler Upgrade Scheme.
- The UK plans to phase out new gas boiler installations by 2035.
- Always use Gas Safe registered engineers and compare at least three quotes.
Frequently Asked Questions
How long does a boiler installation take?
A like-for-like replacement typically takes one day. Switching boiler type or adding a heat pump may take two to three days.
Are hydrogen boilers available now?
Hydrogen-ready boilers are available and run on natural gas today. They can be converted to hydrogen if and when the hydrogen grid is rolled out.
Will my gas boiler be banned in 2035?
Existing gas boilers will not be removed or banned. The 2035 target relates to the installation of new gas boilers, not existing ones.
Written by
Mike Henley
Gas Safe Registered Engineer
This guide has been written and fact-checked by a qualified professional to ensure accuracy. All information is regularly reviewed and updated. Wisehande editorial standards require expert authorship and peer review for every guide we publish.
