Hybrids for heating that won’t cost the earth

Mitch Cogger, International Product Manager, Intergas Heating Solutions, discusses the benefits of hybrid heating systems.

Ever since former Prime Minister Boris Johnson pushed the Heat Pump agenda, it may have appeared to many that this is the Holy Grail of energy efficiency, the means by which the country’s reliance on fossil fuels could be stopped in its tracks and the Government’s commitment to reach its net zero target by 2050 assured. But the reality is different. For some installers, many of whom have never installed a heat pump and don’t have the F-Gas qualification, the prospect of training in a new technology is just plain scary; they may also be praying for hydrogen to come on stream so they can carry on fitting boilers. But there are installers out there who recognise that heat pumps are here to stay and, if they’re 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 is around £14,0001, although you can deduct the £5,000 BUS grant from that, and your property must be well-insulated to truly benefit as flow temperatures run a lot lower than that of a boiler. And don’t forget the spark gap. At the moment electricity is around three times more expensive per kilowatt hour than gas2 so there’s a perception that gas is more affordable, making fossil fuels appear all the more attractive and, of course, this impacts on environmental targets. This June, the Climate Change Committee’s (CCC) annual progress report warned that there’s ‘markedly less’ confidence in the UK’s ability to meet its decarbonisation targets from 2030 onwards3. Something needs to be done.

Reduce costs and lower household disruption
Given all these factors, hybrid heating systems 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 ErP boiler (providing it has OpenTherm on/off controls) retained, the overall cost of installing a hybrid is significantly lower than that of a stand-alone heat pump. First, if the boiler’s a combi there’s no need to install a cylinder as you’ve already got your hot water source from the boiler; with a stand-alone heat pump you’d have the expense of a separate heat pump 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 need to be fitted. And third, this is a faster, easier installation for the installer and good news for the homeowner; the heat pump will heat the radiators for the majority of the year, and when there’s 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 could cut gas consumption by up to 82.5% based on trials) and, as the boiler isn’t working as hard, it’s lifespan could be extended. In fact, some savvy boiler manufacturers are offering to increase the warranty on their boilers when 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. If you’re in Scotland, then you’re in luck as hybrids are included; Home Energy Scotland have grants, similar to BUS, where homeowners can access grants of £7,500 plus an optional loan of another £7,5004.

Heat pumps, when used as part of a hybrid heating solution, make sound financial sense, but retrofitting hybrids to just a fraction of the estimated 23m boilers installed in the UK5 would make a difference that benefits all of us.


  1. www.energysavingtrust.org.uk/advice/air-source-heat-pumps
  2. www.theecoexperts.co.uk/blog/electricity-more-expensive-than-gas
  3. www.theccc.org.uk/publication/2023-progress-report-to-parliament
  4. www.homeenergyscotland.org/heat-pumps/grants-and-funding
  5. www.boilerguide.co.uk/articles/gas-boiler