Heat pumps: is it worth replacing your gas boiler?

In October last year, during the run-up to the Cop26 climate change conference, the UK government announced plans to subsidise the introduction of low-carbon heat pumps in order to cut reliance on fossil-fuel heating.

As part of a “home heating revolution” in Britain, the government set out plans to start phasing out gas boilers by offering £5,000 grants to help 90,000 households install home heat pumps, The Guardian said. 

For 50 years the gas boiler has been “the mainstay of central heating”, said The Times. “Its days, however, are numbered” as new gas-reliant boilers will be banned from UK homes by 2035. Although the government is considering a number of green alternatives to heat homes, including the use of hydrogen boilers, the most “viable” alternative for the majority of households will be electric-powered heat pumps. 

Climate change is not the only crisis that Britain is battling – there’s also the cost of living crisis, too. The three-year boiler upgrade scheme will help “reduce the cost of more environmentally-friendly heating systems”, the BBC reported. And in his Spring Statement last month, Chancellor Rishi Sunak also announced that households will now pay 0% VAT on energy-saving equipment such as heat pumps and solar panels. 

With energy bills going through the roof, can households afford to make the switch from gas boilers to heat pumps? 

What are heat pumps and how do they work?

An electric heat pump works like “a reverse fridge, extracting warmth from the outside air, the ground or a nearby water source before concentrating the heat and transferring it indoors”, The Guardian explained.  

Heat pumps are “nothing new”, said The Times, but very few are installed each year – roughly 27,000. The number of heat pumps being installed in UK homes will have to be scaled up considerably, with Boris Johnson’s climate advisers recommending that “by 2030 there should be 5.5 million heat pumps in British homes”.

Heat pumps work even when outside temperatures are very low and near freezing. They are also “much more efficient than a gas boiler” as they are able to produce “around three times the energy they use”, said the i news site. 

“Crucially, heat pumps are also clean”, The Times added. Gas-reliant boilers produce masses of carbon dioxide: the gas boilers in British homes “produce twice as much CO2 as the nation’s gas-fired power stations”. But if we can ensure the electricity used to power heat pumps comes from “truly green sources” then “water is the only byproduct” of using a heat pump.

How much do heat pumps cost to install? 

The cost of installing a heat pump can be significant and depends on the type installed and the size of a property, the BBC said. The installation can also prove to be “difficult and expensive”. For example, you may need to install “bigger radiators or dig into floors”. 

Heat pump prices are “usually high, taking into account the installation”, said GreenMatch.co.uk. The typical price range for a complete installation is “between £8,000 and £45,000, to which the running costs have to be considered”. The cost for an air to water heat pump range from £7,000 to £18,000, while ground source heat pumps can cost up to £45,000. “The running costs of heat pumps depend on your household, its insulation properties and size.”

What grants are available and who is eligible? 

Through the boiler upgrade scheme, government grants will be provided to encourage property owners to install low-carbon heating systems such as heat pumps, the Department for Business, Energy & Industrial Strategy explained. The scheme is open to domestic and small non-domestic properties in England and Wales and runs from 2022 to 2025. “These grants will help property owners overcome the upfront cost of low carbon heating technologies.”

From 1 April, if the installation and system set-up of a low-carbon heating system is completed then support will be entitled under the scheme. From 11 April installers will be able to open an account for the scheme with administrator Ofgem, and from 23 May the scheme opens for grant applications and payments.

Entitlements include: 

• £5,000 off the cost and installation of an air source heat pump
• £5,000 off the cost and installation of a biomass boiler
• £6,000 off the cost and installation of a ground source heat pump

What are the advantages of heat pumps? 

Heat pumps are “normally three times more efficient than gas boilers but they use electricity to run, and electricity prices are typically more expensive than gas”, the BBC said. However, given the current high price of gas, “heat pumps could still be cheaper”. The government has said it will look at ways to ensure heat pumps are “no more expensive to run than a gas boiler in the long run”.

There are seven main advantages of heat pumps, according to GreenMatch.co.uk. These are: 

• Lower running costs
• Less maintenance
• Better safety
• Reduces carbon emissions
• Provides cooling
• Long life-span
• Eligible for RHI scheme

What are the disadvantages? 

Although the government is setting aside £450m for the new subsidies, this will only cover the cost of replacing around 90,000 boilers. Homes also need to be well insulated to stay warm with the use of a heat pump, which not only adds to costs but the “high levels of insulation needed” is not “always possible in older, solid-walled homes common across the UK”, the BBC said.

Installing a heat pump “might not be the best option for your home, and the cost could be prohibitive”, said The Telegraph. “Although the technology is evolving, and is likely to improve significantly and fall in cost over the coming years, heat pumps are currently slower at heating cold homes than traditional boilers.”

Space could also be an issue because you’ll “need a place outside your home where a unit can be fitted to a wall or placed on the ground”, said the Energy Saving Trust. “It must have some space around it to allow a good flow of air.”

Seven main disadvantages of heat pumps are, according to GreenMatch.co.uk:

• High upfront cost
• Difficult to install
• Questionable sustainability
• Requires significant work
• Issues in cold weather
• Not entirely carbon neutral
• Planning permissions required

Kevin McCloud, presenter of TV show Grand Designs, believes spending millions on heat pumps is a “classic pratfall”, The Telegraph reported. In an interview with the paper McCloud said while heat pumps are “wonderful machines”, and he’s a “big fan”, Britain should be focusing on insulation, ventilation and shutters instead.