UK Edition
Homeowners trying to install eco-friendly heat pumps have been left with surprise £30,000 bills after it emerged millions of radiators are too small to work with the new technology.
The Government wants 600,000 heat pumps installed every year by 2028, in line with its “net zero” aims, but the majority of homes may need thousands of pounds worth of upgrades to accommodate them.
Heat pumps need larger radiators to achieve the same heat output as gas boilers, which heat water to much higher temperatures.
Some 99pc of British homes do not have radiators large enough to heat a room on the coldest winter's day, using a low-temperature heat pump, the most common model, according to a Department for Business, Energy & Industrial Strategy study. "High temperature" heat pumps can help fix this but 90pc of homes would still need better radiators.
To heat a home on an average winter's day, 94pc of British households would need to upgrade their radiators if using a standard heat pump.
Gas boilers achieve temperatures of around 70°C, but most air source heat pumps operate at around 35°C to 45°C for the radiator system and around 55°C for hot water.
The Department said the typical costs for buying compatible radiators would be £1,700 for a one to two-bedroom house, £2,200 for a three-bedroom house, and approximately £2,900 for a five-bedroom house. However, this does not include the labour cost of fitting a new heating system.
Some customers have been hit with much higher bills. Michael York, 83, was quoted nearly £30,000 to install a heat pump and replace all his radiators.
Mr York said: "Last year my 19-year-old boiler was making a funny noise and I decided it was time for an upgrade. I looked into a heat pump, because of the Government's interest in them.
"I consulted a heat pump specialist who said the installation cost for a suitable heat pump and changing all the radiators was nearly £30,000. My house was built in 1976, it’s detached, it has cavity wall insulation, and double glazing. It's very well insulated."
Mr York said the specialist told him there were several rooms in his home that would not be able to accommodate radiators large enough to achieve the same heat output as his gas boiler. "The prices have come down and it would now cost around £20,000, but I didn't want to spend that when I could just pay £2,400 for a new gas boiler."
Andy Kerr of Boxt, a gas boiler retailer, said: "Most houses that have a heat pump installation will need to have at least one radiator replaced.
"Heat pumps also require a water storage tank, which many properties no longer have due to the popularity of combi boilers. It is a complex installation and usually requires the whole central heating system to be replaced."
The Government offers grants of up to £5,000 to replace a gas boiler with a low-carbon alternative. The £450m scheme is expected to cover about 90,000 installations over three years.
The National Infrastructure Commission, which advises the Government, said it was investigating ways to fund the transition and encourage the take-up of heat pumps. A spokesman added: "There are still major questions to be answered, including what level of insulation will be needed to efficiently operate heat pumps, whether hydrogen for heating will be available, and how to deliver these major changes in people’s homes."
A spokesman for BEIS said: "Gas boilers are expensive to run, whereas electric heat pumps are more efficient. Anyone who chooses to install a heat pump can claim a grant worth up to £5,000 and will also benefit from 0pc VAT.
“We are working with industry to further bring down the cost of heat pumps by up to half by 2025 as the technology develops, making them ultimately the most affordable and sensible option.”