Since 2005 virtually all gas boilers that have been fitted in the UK are more efficient typically around 90% (an A or B energy efficiency rating). These new boilers are called ‘condensing boilers’. Condensing boilers have bigger heat exchangers that recover more heat from the burning gas, making them more efficient. Your boiler will be a condensing boiler if the following points are true:
- The flue is made of plastic. If it is made of metal it’s unlikely to be a condensing boiler.
- The boiler has a plastic pipe coming out of the bottom, through the wall and into a drain.
- It was installed after 2005 (if it’s a gas boiler).
- It was installed after 2007 (if it’s an oil boiler).
Government replacement gas boiler scheme
The aim of Government’s Energy Company Obligation (ECO) boiler grant scheme is to reduce the cost of heating bills for those living on a low family income in the UK (excluding Northern Ireland). The UK’s ‘Big Six’ energy providers fund the boiler grant scheme. It enables homeowners or private tenants who receive benefits related to their income to upgrade their boiler for free.
You do not need to be a customer of British Gas, EDF, nPower, e.on, SSE or Scottish Power to apply for a free boiler, you can apply to any supplier who is running the scheme. Contact your energy supplier to find out if you are eligible or search ‘Replacement gas boiler scheme’ online.
The typical cost of a replacement gas boiler is estimated between £2,000 and £2,500.
Once installed, the average household could expect to see a reduction in their annual gas bill by as much as £300 as a result of the new boiler being much more efficient.
Note: the cost of any additional work, like fitting new radiators or pipework, is not covered under this scheme.

Do you qualify for a Government grant for a new boiler?
To qualify for a free replacement gas boiler grant, you need to meet certain criteria relating to your household circumstances and your current gas boiler. The current replacement boiler scheme requires:
- Your household income is less than £15,860 and you are in receipt of tax credits, or
- You are aged over 60 and in receipt of Pension Credit, or
- You are on Income Support or Job Seekers Allowance with responsibility for children or a disabled person.
Your current gas boiler needs to be at least seven years old and no longer deemed efficient. The scheme does not include oil or wood fired boilers at present.
Council owned properties and Housing Association accommodation have boiler replacement schemes of their own and are not covered by the government scheme.