The ban on gas boilers is likely to include an exception for hydrogen-ready devices, which work on natural gas but can run on the alternative when it is available.
The Government’s advisers previously said hydrogen will only be suitable in around 11pc of homes, meaning some “hydrogen-ready” boilers could be installed but continue to run on gas.
Meanwhile, heat pumps have also been explored as an alternative. The Government wants 600,000 of these devices installed in homes each year by 2028.
There are two types of heat pumps currently available. Air source heat pumps pull ambient heat from the air and increase the temperature using a compressor. This is then used to heat radiators and water. Ground source heat pumps are similar but draw heat from pipes buried in the ground. These have higher up-front costs but run more efficiently.
Questions have been raised over both the cost of the devices and their effectiveness in heating homes when compared to traditional boilers.
Last month the Business and Energy Secretary Kwasi Kwarteng admitted heat pumps were inferior to traditional boilers, adding that while gas boilers had been “refined over many years … heat pumps are still in their infancy”.
And earlier this month, Chris Stark, the chief executive of the Climate Change Committee, said that the boiler alternatives were “very expensive” and policy changes were needed to make them realistic.
Will my energy bills go up?
Heat pumps are usually powered by electricity, which is much more expensive than gas or oil, but they are three to four times more efficient than traditional boilers. This means running costs are similar, according to the Energy Saving Trust.
The Energy Savings Trust said a standard air source heat pump installed in an average-sized, four-bedroom detached house would be between £395 and £425 cheaper to run a year than an old “G-rated” gas boiler.
It could be between £500 and £550 cheaper than a G-rated oil boiler or up to £1,300 cheaper a year to run than a G-rated LPG boiler. Newer gas and oil boilers are cheaper to run, however, so the savings would be smaller.
Can I get paid to switch?
A Censuswide survey for the RSK Group, the services provider, found that eight in 10 people would be willing to change how their home is heated to reduce the impact on the environment. However, when asked how much they thought a heat pump system might cost, the average estimate was £3,290.
While a replacement gas boiler can cost around £1,000, an air source heat pump full system installation can cost between £7,000 and £14,000, with ground source heat pumps costing between £15,000 and £35,000.
More than half of respondents to the Censuswide survey said the high upfront cost was the most likely reason to persuade them not to install a heat pump. As a result, eight in 10 respondents said they would only install a heat pump system if they received financial support from the Government.