‘You will regret it’: that was one of the most common reactions when my husband and I told friends that we planned to replace our gas boiler with a heat pump.

Some warned that the technology was still too new in the UK. Others had read newspaper headlines about soaring electricity bills or heard stories of heat pumps struggling through cold British winters. Even experienced builders questioned whether a 1930s detached house like ours was really suitable.

To be honest, we had many of the same doubts ourselves. We are not early adopters chasing the latest technology. We are an ordinary family of four living in a detached four-bedroom house in the English Midlands. Like many households, we wanted a warmer, more comfortable home and lower carbon emissions – but we also wanted heating that worked reliably without costing a fortune.

The installation we never planned

Ironically, we never set out to install a heat pump. Our original plan was simply to renovate the kitchen and bathroom and install underfloor heating in the coldest part of the house. Our existing gas boiler still had several years of life left, but the planned changes to the heating system meant that it would need replacing with a larger model to cope with the increased demand.

That prompted an unexpected question. If we were already lifting floors, rerouting pipes and relocating the hot water system, would this be the right time to leave gas behind altogether?

The answer seemed straightforward – until we started looking for an installer, and then struggled to find one that could meet our needs. Ironically, the most useful advice came not from a salesperson but from another homeowner. A neighbour living in a similar style of property had already installed a hybrid heat pump system. They explained how reducing the spacing gaps for pipes providing underfloor heating could compensate for the lower water temperatures produced by heat pumps. That single piece of practical advice transformed our understanding of the technology and eventually led us to an installer who could design bespoke underfloor heating and heat pump systems.

Looking back, it was a reminder that people often trust neighbours more than brochures.

Learning to live differently

In August 2024, after two weeks of work, the installers packed away their tools and left us with a new 12kW air-source heat pump standing in the garden, connected to a 300L hot water cylinder installed in the garage. Underfloor heating had been added to the kitchen and family room, while new windows and doors improved insulation in the two renovated spaces. One thing we deliberately chose not to replace was the radiators – we wanted to see how they performed before making any further decisions.  

We then began the journey of adapting to life with a heat pump.  

For decades, British households have learned to think like gas boiler users. We turn the heating on when the house feels cold and switch it off once it becomes warm. On winter mornings, the boiler springs into life before we wake, filling the radiators with almost untouchably hot water. Warmth arrives quickly, exactly when we expect it.  

A heat pump works on a completely different principle. Instead of producing intense heat over short periods, it works most efficiently by supplying gentle, continuous warmth.  

It sounds like a small difference. In practice, it requires us to rethink almost everything we had learned about heating our home.  

We gradually realised that the radiators no longer needed to become scorching hot because they were no longer trying to heat a cold house as quickly as possible.

Comfort no longer came from bursts of heat. It came from stability.  

We had begun learning how to live with a different kind of heating system.

We allowed the temperature controls and automatic scheduling to do what they were designed to do. The flow temperature for space heating was reduced to around 45°C, significantly lower than the 70°C typical of our previous gas boiler. Hot water was normally heated to around 45°C as well, with the system automatically increasing the temperature once a week to carry out a Legionella protection cycle during an off-peak electricity period.

The unexpected power of everyday habits

One of the biggest criticisms of heat pumps is that electricity in Britain remains much more expensive than gas. The good news is that, unlike gas tariffs, electricity prices are becoming increasingly flexible.

We switched to a time-of-use tariff offering three off-peak periods each day (04.00–07.00, 13.00–16.00 and 22.00–01.00, see Figure 1), when electricity was around half the normal price (the standard tariff), alongside a more expensive evening peak between 16.00 and 19.00.

Figure 1: Seasonal hourly average electricity consumption

Note: Elec = electricity 
 

At first, the tariff looked complicated. Then we realised it wasn't asking us to use less electricity. It was asking us to use it differently. The dishwasher no longer started immediately after dinner. The washing machine and tumble dryer were programmed to run overnight or during cheaper afternoon periods. The hot water cylinder reheated automatically when electricity prices were lower. Even cooking gradually adapted to the new rhythm of the tariff.

None of these changes felt inconvenient. Most became routine within a few weeks, largely because timers and smart controls did the work for us.

The most interesting adaptation, however, involved the house itself. The renovation had included underfloor heating in the kitchen and family room – the two coldest rooms in the house. Unlike radiators, underfloor heating responds slowly but retains warmth for much longer. Instead of heating these rooms during the expensive evening electricity peak between 16.00 and 19.00, we allowed the floor to warm beforehand while electricity was cheaper. During the peak period, the stored heat continued to warm the rooms naturally. Radiator-heated areas of the house were allowed to cool before heating resumed when electricity prices fell again. The heated floors became one large, low-temperature radiator, warming the entire house.

Without really noticing it, we had started thinking differently about our home. The building itself had become part of the heating system. Walls, floors and furniture all stored warmth, reducing the need to generate new heat every time the thermostat changed.

Looking back, this represented a subtle but important shift in behaviour. Instead of demanding instant warmth, we planned ahead. And instead of seeing electricity as something consumed at a fixed price, we began treating it as a resource whose value changed throughout the day. After almost a year, these habits no longer felt like adaptations. They had simply become normal.

The numbers behind the story

Our monitoring data (which have been published in a peer-review paper) later confirmed what we had experienced in everyday life. Our actual demand was around 26% lower than the annual energy demand assumptions made when the heat pump was designed. Our annual demand fell by 18% compared with the previous three years using the gas boiler.  

The difference was largely the result of how we lived with the system. By maintaining slightly lower but more consistent indoor temperatures, making greater use of underfloor heating and shifting electricity use away from expensive periods, we reduced the amount of energy the house actually required.

The heat pump itself also exceeded expectations. Across the first year of operation, it achieved a seasonal performance factor of 3.22. In simple terms, every unit of electricity purchased delivered more than three units of heat to the house.  

Not everything was perfect. The annual energy bill fell by only around 12%, despite a 59% reduction in energy consumption. Britain's high electricity prices continued to limit the financial benefits of the technology. Yet by shifting much of our electricity use into cheaper tariff periods, we reduced the effective price by around 3p/kWh. It was not enough to eliminate the gap between electricity and gas costs, but it showed how changing everyday habits could make a meaningful difference.

A different way of thinking about home heating

Much of the public debate asks whether heat pumps work. Based on our experience, that is the wrong question. The better question is whether we are prepared to use them differently. Heat pumps are not simply another appliance replacing the one before it. They ask homeowners to think differently about comfort, energy and daily routines. Fortunately, those changes are far smaller than many people imagine.  

Technology can only take us so far. The rest depends on ordinary households making small, practical changes that, together, can make low-carbon living both comfortable and affordable. Technology opens the door, but it is the people who determine how far to walk through it.

The views and opinions expressed in this article are those of the author and do not necessarily reflect those of the Energy Institute.

• Further reading: ‘Smart heat pumps: the potential for demand flexibility in the home’. A new study has demonstrated the transformative potential of smart heat pumps, not just as efficient heaters, but as powerful tools to support the management of the UK’s electricity system.
• ‘A smarter way to heat Europe’s homes’. Heat pumps offer economic, environmental and energy security advantages over fossil gas boilers for domestic heating, and represent a fully proven technology in parts of northern Europe. Time for the rest of Europe to catch up, argues Kaj af Kleen, Chief Product and Technology Officer at heat pump company Aira.