Heating engineer sees big savings in switch from combi boiler to heat pump 

Humberside homeowner James Clark scrapped the gas combi boiler at his three-year-old house in Welton. All heating and hot water are now provided by a Daikin air source heat pump that is partly powered by batteries and rooftop solar panels.

Tell us about the house and the new system

It’s a two storey detached house with three bedrooms. We now have a 3.4kW Daikin Altherma monobloc heat pump and a 180-litre Daikin hot water cylinder. The cylinder is mounted in the loft as the house was not built with ‘airing cupboard’ hot water storage.

Why did you decide to make the change?

We have been installing air source heat pumps for about seven years and have increasingly used Daikin systems. My problem was that I was selling heat pumps but did not have one in my own house – and customers kept asking if I did.

Was the change expensive?

The Boiler Upgrade Scheme’s £5,000 up front meant it was the perfect time for my family to go green. [Note: The BUS grant has now been raised to £7,500] 

What other benefits did you find?

I have the Daikin Onecta app on my phone and I've been checking my SCOP (seasonal co-efficient of performance) since installation. We're currently running close to 430% efficiency (SCOP 4.29).  And I’ve been learning a lot about the controls, which are excellent. 

How will your solar panels help?

I can definitely say that the heat pump will save about 25-30% of normal gas boiler running costs. But if you couple it with solar panels and battery storage you’ll save perhaps 60-70%. I’ve had up to 20kWh of electricity over 24 hours, but I reckon 10-12kWh of solar power is still a good day.

Will this help your business?

I wanted this to be a trial and a showpiece: What the future holds is solar panels, a  battery and a heat pump – creating your own fuel to get easily 60% off your bills. Now I can show customers that we can cut our carbon footprint and help achieve the UK's Net-Zero targets – while saving money.