Ever since then Prime Minister Boris Johnson brought heat pumps to the forefront of the energy efficiency agenda, they have been considered the primary means by which the country’s reliance on fossil fuels could be stopped in its tracks and the government’s commitment to reaching its net-zero target by 2050 assured. 

The reality is different, however. For some installers, many of whom have never installed a heat pump and don’t have the F-Gas qualification, the prospect of training for a new technology is intimidating. They may also be praying for hydrogen to come on stream sooner rather than later, so they can carry on fitting boilers. 

But there are installers out there who recognise that heat pumps are here to stay and that, if they are trained, they won’t be short of work. The only fly in that particular ointment is the cost to the homeowner. 

The current cost of living crisis, which means there are homeowners who won’t even pay to have their boiler serviced, is a huge deterrent to adopting this technology at the moment. 

The installation is a sizable financial commitment: the Energy Saving Trust says a typical air source heat pump (ASHP) installation costs around £14,000 – although you can deduct the £5,000 Boiler Upgrade Scheme (BUS) grant from that, and your property must be well-insulated to truly benefit as flow temperatures run a lot lower than those of a boiler. 

And let’s not forget the ‘spark gap’. At the moment, electricity is around three times more expensive per kilowatt hour than gas, which creates a perception among consumers that gas heating is more affordable, and, in turn, impacts on environmental targets. 

This June, the Climate Change Committee’s annual progress report warned that there is ‘markedly less’ confidence in the UK’s ability to meet its decarbonisation targets from 2030 onwards. Something needs to be done.

Reduced costs and disruption

Given all these factors, hybrid heating systems are starting to look like good news. 

A hybrid heating system consists of a gas boiler, an indoor control unit, and an ASHP. Whether a new boiler has to be fitted, or the homeowner’s existing ErP boiler (providing it has OpenTherm on/off controls) is retained, the overall cost of installing a hybrid system could be significantly lower than that of one powered by a standalone heat pump. 

First, if the boiler is a combi there is no need to install a cylinder, as that boiler already provides the hot water. With a stand-alone heat pump you would have to factor in the added expense of a separate cylinder. 

Second, providing a heat loss calculation has been made and the radiators have been correctly sized and flushed, they may not need to be changed. With a heat pump, due to the low flow temperatures mentioned earlier, a greater surface area is needed to meet the heat demand, so new radiators will likely be needed. 

And third, installation is faster and easier for the installer, and running costs are lower for the homeowner. The heat pump will heat the radiators for the majority of the year, and when there is a really cold snap, the boiler takes control, so both carbon emissions and gas consumption will be lower overall. 

Some hybrid manufacturers are claiming reductions in gas consumption of over 70% (the Intergas Xtend, for example, could cut gas consumption by up to 82.5%, based on trials) and, as the boiler isn’t working as hard, its lifespan is likely to be extended. In fact, some boiler manufacturers are offering to increase the warranty on their boilers if they are fitted as part of the hybrid heating system. 

Unfortunately, hybrids currently aren’t eligible for the BUS grant in England and Wales, which is a pity as it would drive interest in decarbonising homes, and help towards reducing heating costs. 

In Scotland, however, hybrids are included in support schemes. Home Energy Scotland offers grants, similar to BUS, where homeowners can access financial support of £7,500, with the option of a loan of another £7,500.

Heat pumps, when used as part of a hybrid heating solution, make sound financial sense, and retrofitting hybrids to just a fraction of the estimated 23 million boilers in operation in the UK would benefit all of us.