Adam lives in a 1930s three-bedroom semi-detached house in the north of England. He recently replaced his gas combi boiler with a Vaillant Arotherm heat pump and Sunamp Thermino heat battery.
The main motivation for Adam and his wife when improving their home was to reduce their energy bills as far as possible to give them more disposable income when they retire.
The challenge – finding a compact hot water solution to work with a heat pump
Energy bills were Adam and his wife’s second biggest expense after their mortgage, so they were keen to bring down the cost of heating and hot water in particular. Adam has a professional interest in how smart technology can improve energy efficiency and bring down fuel bills, and is always keen to try out new technology in his own home.
Adam already had solar panels and electric batteries alongside his gas combi boiler, and was looking to switch to a heat pump using funding from the UK Government’s Boiler Upgrade Scheme. Heat pumps funded under the scheme must provide both space heating and hot water, with a hot water cylinder often used to meet this requirement.
This was an issue for Adam, who explains, “We went through every single room in the house and there wasn’t space anywhere to put a hot water tank without basically losing a room. Ours is quite a compact house so we weren’t prepared to do that.”
Adam’s boiler was housed in a small and narrow utility room which wouldn’t fit a hot water cylinder. When looking into the options Adam came across Thermino heat batteries, a compact alternative to a hot water cylinder which would fit perfectly in the small space.
The solution – a space-saving and efficient Thermino heat battery
Adam did a lot of research into the difference between a Thermino and a hot water cylinder before making his decision. He explains, “I thought actually, this is the way to go. You’re not actually storing water, you’re storing heat in a different way. I can see it’s got less moving parts or things to fail in it, less entry points for water and less water being held, which means you don’t get problems like corrosion or legionella either.”
This suited Adam as he was looking for a ‘fit and forget’ solution. He contacted Sunamp to confirm that a Thermino would be eligible for funding under the Boiler Upgrade Scheme when combined with a heat pump, then searched for a local installer on the Sunamp website.
Adam chose a fairly large firm who could complete both the heat pump and Thermino installation as a package, as he didn’t want to have to manage different contractors doing different parts of the job. Adam’s installer surveyed his home, did heat loss calculations, and recommended a Vaillant Arotherm 7kW heat pump with a Thermino 210 e heat battery, which is the equivalent of the Thermino ePlus in the latest range.
In preparation for the install, Adam dug a trench in his garden for the primary pipes and built a table for the Thermino to sit on which could bear the weight of the heat battery while still allowing Adam’s washing machine to fit underneath, making best use of the space in the small utility room.
The heat pump and Thermino cost around £16,500 including installation, but Adam got a Boiler Upgrade Scheme grant of £7,500 and a further £2,000 Green Homes Reward from his mortgage provider Barclays. As he said, “This makes £9,500 off a £16,500 bill, so it would be stupid not to do it!”
Although the upfront cost of the Thermino was more than a traditional hot water cylinder, Adam believes this will be worth it over time due to the longevity of the system and the fact that it has much lower heat losses than a cylinder.
The benefits – lower bills, reliable hot water and a future-proofed home
Adam’s main priority when changing his heating and hot water system was to bring down his energy bills. By taking a whole-house approach and monitoring his energy consumption, Adam can make sure he is using energy in the most efficient and cost-effective way.
The combination of solar PV, electric batteries and a Thermino heat battery means Adam is able to buy electricity overnight at a cheaper rate of around 12p per kW and store this until he needs it. He can then use the stored energy to power his appliances and run his heat pump from the electric batteries and provide hot water through the Thermino. This approach is certainly paying off for Adam as his energy costs are down to around £25 a month – well below the UK average monthly electricity bill of £80.
Adam uses the Zigbee network to control and monitor his energy use, and has connected his Thermino to a Zigbee switch which detects when his heating element is looking for power. He can then decide how to meet this need, whether through the heat pump which runs at 3kW but will output 6kW thanks to its high coefficient of performance, his solar panels if it’s sunny and he’s generating free energy, or using electricity stored in his electric batteries.
As it’s still a fairly new system, Adam is working out how often the Thermino needs charged in order to provide enough hot water for his household. So far, he hasn’t ever let it go empty or run out of hot water, and has used it for two days without recharging.
Mains pressure hot water on-demand, guaranteed
Along with reducing his energy costs, it was essential for Adam to have a reliable supply of hot water as his wife runs a dog grooming business from home.
Adam explains, “It’s very important for us to have an uninterrupted hot water supply, which was one of the reasons why I went for the Thermino – it needed to have very little chance of failure and to have the option to charge from the heat pump or from grid electricity. I could have done that with a hot water tank but I didn’t think this would be the most efficient option as it’s very old technology.”
The option of charging the Thermino using backup grid electricity came in handy when Adam’s heat pump wasn’t running due to a fault. He charged the Thermino with 10kW of electricity overnight which cost around £1.20 and gave him and his wife plenty of hot water for showers and dog grooming throughout the day.
A future-proofed home which is worth the investment
Another benefit of switching to a heat pump and heat battery is that Adam is no longer using any gas to heat his home and is due to have his gas meter removed. He said, “There’s no future for hydrogen or gas, simple as that. The future is electric.”
Next, Adam is increasing his electric battery capacity, meaning he will have 30kW of electric batteries in total along with his 7kW of solar panels. Adam is also considering fitting external wall insulation which should reduce his home’s heat loss and therefore reduce the demand on his heat pump, bringing his energy costs down even further.
Adam has invested a lot in his home but is pleased to have achieved such low energy bills as a result. He explains, “I’ve invested about £40k in solar panels, batteries, a Thermino and an air source heat pump to reduce my energy costs, but all I’m really doing is taking my energy bills for the next 30 years and upfronting them. Our house is now basically cost neutral.”
It’s very important for us to have an uninterrupted hot water supply, which was one of the reasons why I went for the Thermino – it needed to have very little chance of failure and to have the option to charge from the heat pump or from grid electricity."
Adam, homeowner in the north of England