At Renewable Heating Hub, we run a quote and proposal review service. Ten to fifteen proposals a month arrive from homeowners who are confused by what they’ve been told, suspicious of what they’ve been quoted or simply trying to make sense of a decision that will cost them the best part of ten thousand pounds. The numbers are modest. The patterns are not.
What those proposals reveal (consistently, across installers of varying size and reputation) is an industry that routinely overpromises. Not always cynically. Not always intentionally. But routinely.
The kW badge is the most common offender and arguably the most misunderstood. The figure printed on the side of a heat pump is almost universally a best-case measurement… typically taken at seven degrees outside and thirty-five degrees flow temperature. Conditions that describe a mild autumn afternoon, not a January cold snap. At minus two, that same unit might deliver considerably less output. Precisely when the home needs it most.
Zero and minimal disruption installations have grown rapidly as a model precisely because they make heat pump adoption more accessible. Leave the radiators. Avoid the upheaval. Keep the cost down. In the right circumstances that is a legitimate and honest proposition. In the wrong ones, a master bedroom with high ceilings and three outside walls, flagged by the homeowner as the hardest room to heat with their existing oil system, it becomes the next iteration of the same problem. The radiators are signed off. The room never comes to temperature. The bill arrives.
Buffer tanks generate more confusion than almost any other element of a heat pump installation. Some manufacturers insist they are mandatory. Others say the opposite. Many installers fit them as a default, not because the system design calls for one, but because it is easier, or because the manufacturer requires it to honour the warranty, or because it provides a degree of cover if the commissioning is not quite right. The efficiency cost of a poorly configured four-port buffer, particularly when the secondary-side pump is fixed speed and unmanaged, is real and ongoing. Most homeowners with one fitted have no idea it is there, let alone what it is doing to their running costs.
On bill savings, the honest position is more nuanced than the industry has typically been willing to admit. A well-designed system running at forty-five degrees flow temperature can reasonably expect savings of fifteen to twenty percent against mains gas. At fifty-five degrees (the flow temperature typical of a zero-disruption install) parity is a more realistic ambition. For homes on LPG or oil, the case is considerably stronger. For someone with a functioning gas boiler and no particular reason to change, the honest advice is to wait.
Warranties are perhaps the quietest scandal in the sector. Homeowners are routinely unaware whether they are covered for two years, five, seven or ten, because installers do not always make it clear, and because manufacturers operate tiered schemes where the length of cover depends on the level of brand-specific training the installer has completed. Something goes wrong. They call the manufacturer. They discover their ten-year warranty is actually two because the engineer never completed the right refresher course.
None of this is an argument against heat pumps. The technology works. The problem is not the physics. It is the gap between what is promised and what is delivered and an industry that has not yet decided whether it wants to close that gap or keep selling around it.
