We interviewed 31 out of the 39 Bristol City Council tenants who had their heat pumps audited by Nesta. The interviews captured a diverse mix of residents, many of whom manage long-term health conditions that make reliable warmth essential. The cohort included both long-term tenants who went through a retrofit installation and residents who inherited the system upon moving in. Prior to the heat pump, participants had a wide variety of legacy heating setups, ranging from standard gas boilers and storage heaters to older solid-fuel systems. More details about the participants can be found in the project methodology document.

Mixed satisfaction with heating and bills

While the audits identified issues with the quality of installations in the majority of homes, tenant satisfaction with their heat pumps was mixed. The majority of tenants were satisfied with the steady, consistent warmth and the perceived safety provided by removing gas from their homes. This mirrors findings from previous Nesta work looking at heat pump satisfaction amongst owner-occupiers, which found that heat pump users are highly satisfied with their heat pumps, considering them to be safe, reliable, quiet heat sources.

However, some of the tenants found that the system was too slow to heat their rooms and that their house remained generally cold. Tenants tended to be less satisfied with their hot water provision than with their space heating, with some households finding the supply to be inadequate, occasional scalding water temperatures (from legionella cycles), and breakdowns causing a loss of hot water. Alongside these comfort issues, other residents reported high electricity bills, which were affecting their daily lives. To avoid the high costs, some of these tenants were limiting the use of their heating either by switching the heat pump off completely or by just using it for short periods of time.

Despite the quality issues identified during the audits, many tenants were highly satisfied with their system. In these instances, tenant experience was heavily driven by expectations carried over from their previous heating setups. Positive perceptions were especially strong among tenants who previously relied on storage heaters. Because traditional storage heaters have high running costs and poor heating experiences, the switch to a heat pump represented an upgrade in both daily comfort and affordability, with some residents finding that switching resulted in lower running costs compared to their previous system. Conversely, tenants who transitioned from gas boilers were more likely to be frustrated, often preferring their old system's ability to quickly blast intense heat over short periods rather than adapting to the steady, low-temperature warmth of a heat pump.

These findings align with research findings by the University of Bristol, which identified a ‘satisfaction paradox’ where residents remain highly satisfied with heat pumps despite technical underperformance, provided their baseline comfort and personal expectations are met. A recent report by Carbon Trust for the Committee of Fuel Poverty also found that “participant satisfaction levels were driven primarily by a comparison with their previous heating systems, many of which were expensive, unsafe or not working”, but that “self-reported satisfaction did not reliably indicate that the system was operating well and delivering low fuel bills”.

In our case studies below, names have been pseudonymised and specific personal details redacted or generalised to protect participant anonymity.

Low levels of heat pump knowledge

Tenants generally displayed low levels of heat pump knowledge. Some were not aware that they had a heat pump, referring to their system as a “boiler”. Without an understanding of how heat pumps work, residents used the system like a traditional gas boiler, heating their homes in short, intense blasts instead of continuously, which likely negatively impacted the system’s performance and, as a result, the tenants’ running costs. Many tenants also struggled to understand their controls, with thermostats not being used and a lack of set schedules. A number of tenants controlled their heat pumps by turning the power off completely.

This widespread lack of knowledge stems largely from poor handover processes during installation or when a new tenant moves in. Residents who inherited a heat pump upon moving into a property showed the lowest awareness of how to operate it, while tenants who were present for the installation during their tenancy had slightly better awareness. Many recalled being told how to use the heating on moving day but could not remember the details because they were overwhelmed with information at the time. Instead of simple, practical guidance on how to run their system efficiently, most residents were handed thick, overly technical manufacturer manuals.

Mixed experience of maintenance

Tenants' experience of having their systems serviced and repaired was mixed. Some tenants could not recall receiving a service visit since their heat pump was first installed, while others reported having annual visits. Some tenants complained that attending engineers were often unfamiliar with heat pumps and were unable to resolve issues, resulting in repeated visits by different staff members to rectify a single fault. Although some tenants described frustration over the speed and quality of repair visits, several reported highly positive experiences, with engineers arriving within hours of reporting faults.