Understanding how heat pumps work.
First things first, when talking about heat pumps, it’s worth noting that there are two main types - air source heat pumps and ground source heat pumps. Both types extract heat from their surroundings, and use that heat to run a heating system.
But how do the heat pumps work? Well, a simple analogy is that heat pumps work a little like a fridge, but in reverse. Air source heat pumps contain a liquid (a refrigerant) that absorbs heat from the outside air (even in temperatures as low as -25°C). The heat pump then compresses the liquid to increase its temperature and transfers the heat to your heating system.
Air source heat pumps can heat your water up to 45-55°C, more than enough for your radiators and taps. They use a small amount of electricity to work.
Ground source heat pumps work a little differently. They use a loop of pipe laid horizontally in trenches or vertically in a deep bore hole filled with a fluid that extracts heat from the ground. They then use this heat to warm your radiators, underfloor heating systems and hot water in your home.
As ground source heat pumps take heat from the ground, it does mean you need to have a good-sized garden or outdoor space to install one.
Do the savings stack up and are heat pumps worth investing in?
It’s true that the installation costs of a heat pump are more than those of a boiler installation. For an average sized three-bedroom house, the cost can be between £7,000 and £16,0002. But don’t forget that under the Boiler Upgrade Scheme, you could be eligible for a grant of £7,500 towards a new heat pump for your home. The Boiler Upgrade Scheme is part of the government’s £3.9 billion Heat and Buildings Strategy. If you’re an E.ON Next customer, you can also get an additional £350 off a heat pump too! T&Cs apply.
To work out whether a heat pump will save you money in the long run, you need to do your best to calculate a payback period. You can do this by getting a quote from your installer that will tell you the cost of installing a heat pump and an estimate of the energy usage of a heat pump vs your current heating system. The Energy Saving Trust estimate that a heat pump could save you up to £240 a year compared to an average G-rated gas boiler3.
However, it’s also worth keeping in mind that the payback period is not the only thing to consider when choosing your home heating system. We would rarely expect a boiler to pay itself back. So, it’s worth weighing up all the benefits before making a decision.
Heat pumps can last for 20-30 years or longer and maintenance costs are low. Usually an annual service is enough, so you won’t need to factor in much budget for this. Gas boilers also require annual servicing and generally only last about 15 years.
Don’t forget the desirability factor too - a heat pump could make your home more attractive to buyers who are interested in energy efficiency and sustainability, potentially increasing its value should you come to move.
Environmental impact: heat pumps and your carbon footprint.
Now we’ve covered the costs and savings side of heat pumps, let’s jump into the potential carbon emissions savings you could achieve with a heat pump. Here’s a quick run through for heat pumps vs the most common current home heating systems.
Air source heat pumps vs gas boilers.
Against a G-rated boiler, an air source heat pump could save about 2,900 kg/year of carbon4. That’s the same amount of carbon as 12 return flights from London to Barcelona5. For an A-rated boiler, this figure drops, but to a still impressive 1,900 kg/year4
Air source heat pumps vs oil boilers.
Here’s where the carbon savings really stack up. Against a G-rated oil fueled boiler a heat pump could save a whopping 4,400 kg/year.4 That’s the same amount of carbon as 5 return flights from London to San Francisco6 ! For an A-rated oil boiler, it’s 2,900 kg/year.4
Air source heat pumps vs LPG boilers.
The carbon savings of a heat pump over an LPG boiler are significant too. Against a G-rated LPG boiler, an air source heat pump could save you 3,400 kg/year, and 2,200 kg/year for an A-rated version.4
The above carbon savings figures are based on electricity in general.
How do heat pumps compare to traditional heating systems?
So we’ve looked at the basics and carbon comparisons, let’s look at costs and other differences between heat pumps and traditional heating systems.
One thing that can be said about heat pumps over most other traditional home heating systems is that they can be safer. This is because heat pumps don’t rely on combustion to run - they only use electricity and don’t need to burn fuel to generate heat. So there’s less risk of fires or leaks of potentially dangerous, combustible substances.
Air source heat pump vs gas boiler.
Running costs.
How much an air source heat pump can save you on your energy bills depends on the kind of traditional boiler you’re replacing. As noted above, if you’re replacing an old G-rated gas boiler, that could be around £240/year.7 A brand new A-rated gas boiler may be slightly cheaper to run than an air source heat pump, but by just £14/year8 .
Installation.
Gas boilers are the most common type of heating system in the UK, so they’re suited to all property types. They’re quick and easy to install and there are lots of qualified gas engineers around to do installations.
Heat pumps are less flexible because they require outside space for the main unit. Heat pumps are newer to the UK market, so for the moment there are fewer qualified installers around. If you buy a heat pump with us though, professional installation by E.ON is included. E.ON have installed over 4,000 heat pumps into UK homes over the last 15 years.
Air source heat pump vs oil boiler.
Running costs.
Again, the kind of boiler you’re replacing makes all the difference, but there are definitely savings to be made. For a G-rated oil boiler you could save around £510, and £65 for an A-rated one8.
Installation.
If you use an oil boiler at the moment, you’re likely to have an outdoor oil storage tank. In this case, your home may be a good candidate for a heat pump installation.
Air source heat pump vs LPG boiler.
Running costs.
Heat pump savings vs an LPG boiler are likely to be similar to an oil boiler. So about £510 for a G-rated one and as much as £100 for an A-rated boiler8.
Installation.
LPG boilers also require outdoor space for an LPG tank, so chances are your home could be suited to a heat pump.
Energy efficiency: How do heat pumps measure up?
There’s no question that heat pumps are more efficient than the energy-hogging heaters most commonly used in UK houses. In fact, they’re around 3 to 4 times more efficient9 . On average, air source heat pumps can produce three units of energy for every unit of electricity they use. That’s a very impressive efficiency rating of 300%10.
Installation considerations: Is your home heat pump ready?
Heat pumps are certainly contenders for homeowners looking to make the switch from fossil fuels. Having said that, there are a few things to take into account when thinking about buying a heat pump.
Space.
This could be the main practical dealbreaker. Air source heat pumps need a little outdoor space, usually next to an outside wall. Ground source heat pumps need more space and involve excavation for the network of pipes. Most heat pumps also require a cylinder to provide hot water, so if you’re replacing a combi boiler, you may lose a little indoor space too.
Your home’s insulation.
If your home isn’t properly insulated yet, it’s worth looking into doing that before getting a heat pump. This’ll make sure that heat’s not leaking out of your home and that it’s as efficient as it can be. Check whether you’re eligible for the Great British Insulation Scheme to help with the cost of insulation.
Your current setup.
If you are using us to install your heat pump one of our surveyors will visit your home to check its suitability for a heat pump and carry out a detailed survey. They will check your existing radiators and pipework and advise if anything needs upgrading. They will also explain what will need to be done to install an air source heat pump and arrange for you to get a fixed price quote.
Why might I need new radiators?
Heat pumps work at lower temperatures than traditional boilers so you might need to replace some of your radiators with larger ones to ensure sufficient heat can be transferred to heat rooms to the temperature you want. If you already have big radiators then you may be able to keep them.
Because heat pumps operate at lower temperatures they work best if you heat your home all the time rather than letting it get cold and then using lots of energy to heat it up again. We will talk you through the best approach to heating your home and advise you of the most efficient temperature to use at night and when the home isn’t occupied.
Are government grants available for heat pump installation?
Yes, and they’re well worth taking advantage of. In the UK at the moment, the government’s Boiler Upgrade Scheme offers a grant that takes £7,500 off the upfront cost of an air source heat pump installation. To be eligible for the grant you’ll need a valid Energy Performance Certificate (EPC) from the last 10 years, with no recommendations for cavity wall or loft insulation. New build homes aren’t eligible for the Boiler Upgrade Scheme. For full eligibility criteria and exclusions, visit the Government Boiler Upgrade Scheme website.
Get an air source heat pump quote.
Ready to make the leap into efficient, eco-friendly heating? Get a free, no-obligation quote for an air source heat pump (ASHP) installation from E.ON Next. All it takes is a quick online survey for your preliminary quote. After that we can schedule a follow-up phone call to discuss your needs in more detail.