A free replacement boiler. It's not one of those “educational training courses for entrepreneurs” with their nonsense price tags, either. It's a replacement boiler for my central heating. This, I know, would cost me around £4,000 – I once asked a local plumber for an estimate. He asked me if I had central heating and how old my boiler was. If you are an owner/occupier and have a boiler that is at least 15 years old and earn £40,000 or less, you may qualify for a grant of up to £1,000 to help with replacing an old or inefficient boiler, switch from a natural gas to an oil boiler, or switch to a wood pellet or biomass boiler. However, most will qualify for a grant of £400- £600. Free Boiler Grants Available Now. Qualifying homeowners, private tenants and landlords may be eligible under the UK government ECO scheme. Funding is available for mains gas, oil and LPG boilers.