What 3,700 Heat Pump Owners Said After a Winter: the Boiler Upgrade Scheme's Final Evaluation

Nine to 21 months after installation, 91% of Boiler Upgrade Scheme households were satisfied with their heat pump, up from 80% just after it went in. Among owners who could say how their bills had changed, 61% reported a fall and 19% a rise. Owners on time-of-use or heat pump tariffs were far more likely to report lower bills than those on standard tariffs, and servicing turned out dearer than many expected.

The Department for Energy Security and Net Zero published the final evaluation of the Boiler Upgrade Scheme on 24 September 2026. It covers the scheme’s first phase, April 2022 to March 2025, and its most useful part for anyone weighing up a heat pump is the follow-up survey: households that had fitted one with the grant, asked again after at least one heating season. Across two waves, 3,724 of them answered.

The scheme has since been extended to March 2030. The grant is £7,500 for an air source or ground source heat pump, and households heating with oil or LPG can now claim £9,000.

Satisfaction went up with time, not down

Shortly after installation, 80% of owners were very or fairly satisfied with their system. By the follow-up survey, nine to 21 months later, that had risen to 91%, and 64% of those were very satisfied.

On the practical questions:

93% described indoor temperatures as about right, including on the coldest mornings and evenings
94% said hot water temperatures were about right
89% were satisfied with the noise, and 85% during cold weather when the system works hardest
70% had had no problems with the system at all; only 1% made a formal complaint to MCS
48% had their installation finished in five days or fewer

Two findings cut the other way. 42% still used some other heating alongside the heat pump the previous winter, most often an open fire or wood stove, sometimes for comfort rather than warmth. And only 26% felt completely confident programming their system to keep running costs down.

Bills: what owners reported

Asked whether their total energy bills had changed, owners answered across the whole sample like this: 42% decreased, 14% stayed the same, 13% increased, and the rest said it was too early to say, had no previous bill to compare, or did not know. Taking only the owners who could say either way, 61% reported a fall, 20% no change and 19% a rise.

The heating system replaced made a difference:

replacing direct electric heating: 57% reported lower bills
replacing a gas boiler: 52%
replacing an oil boiler: 38%, still twice the share who reported higher bills

These are owners’ own reports, not metered measurements, and the evaluation notes that energy prices rose between the two survey waves.

The tariff mattered as much as the heat pump

The clearest lever in the report is the electricity tariff. Owners on a time-of-use tariff (52%) or a dedicated heat pump tariff (50%) were far more likely to report lower bills than owners on a standard variable or fixed tariff (31%).

Owners noticed. Nearly half (46%) had switched tariff since the installation, and the share on heat pump tariffs rose from 11% in the first follow-up wave to 25% in the second. The evaluation also records that some owners did not know heat pump tariffs existed, and some could not get one without a smart meter.

Fitting other technology at the same time showed up too: 50% of owners who installed a battery reported lower bills, against 38% who did not, and 45% of those who installed solar panels, against 39%.

Servicing costs more than people expected

Just over half (56%) had had their heat pump serviced within the survey window. Finding an engineer was rarely the problem: 81% of those who tried were satisfied. The cost was less popular, with 15% dissatisfied, and some owners found it dearer than servicing their old boiler. Some also found their original installer no longer offered servicing, or that it was limited to manufacturer-approved engineers. Where a warranty depends on an annual service, that cost belongs in the running-cost sums before the heat pump goes in.

What the scheme delivered

Over its first three years the scheme paid £328.2 million in grants for 49,136 installations, against a budget of £450 million that allowed for up to 90,000. Most of the underspend came in the first year; demand picked up after the grant rose to £7,500 in October 2023 and the insulation requirement was dropped in May 2024. The evaluation estimates that 74% of the installations would not have happened, or would have happened later, without the grant. Uptake was higher among households earning over £52,000 a year, which the report puts down to owners still having to fund part of the cost themselves.

Almost two thirds (64%) of owners who had been on the gas grid had disconnected from it since the installation. Most who had not still used gas for cooking.

Read at source on 6 October 2026: the Department for Energy Security and Net Zero’s “Evaluation of the Boiler Upgrade Scheme, 2026” (published 24 September 2026), its final report (executive summary, and the chapters on energy bills, tariffs and servicing), and the publication page listing the property owner survey data tables. The evaluation covers the scheme’s 2022 to 2025 phase; its surveys predate the May 2025 changes to planning rules in England. Scheme rules change; confirm the current position at the official source.