For a long time, heat pumps benefited from a kind of economic tailwind. Electricity was relatively cheap, gas was politically unstable and the narrative was simple: heat pumps are efficient, therefore they’re cheap to run. For many households, that broadly worked even when systems weren’t especially well designed.
That safety net has gone.
As electricity prices have risen over the last few years, something uncomfortable has started to surface: heat pump running costs are far more sensitive to electricity pricing than many homeowners were ever told. Not because heat pumps “don’t work”, but because their real-world performance depends heavily on system efficiency, and efficiency is not guaranteed.
This is where confusion creeps in. Two homes can both have heat pumps, both be “working as designed”, yet have wildly different bills. One household ticks along comfortably. Another quietly dreads winter. The technology isn’t the difference. The system design is.
Flow temperatures that are too high. Radiators sized on guesswork. No proper room-by-room heat loss calculation. Controls set up for convenience rather than efficiency. Each decision might seem small at install stage, but together they lock in higher electricity demand for the lifetime of the system.
When electricity is cheap, those inefficiencies are masked. When it isn’t, they’re brutally exposed.
In response, many homeowners have been pushed towards solutions like Time-of-Use tariffs and home batteries. And to be clear: these can help. Off-peak electricity can reduce costs. Batteries can shift consumption. But neither of these is a silver bullet, and treating them as such is risky.
Tariffs are commercial products. They exist because they make sense for suppliers, not because homeowners need them. If market conditions change, tariffs can be withdrawn, altered, or made less generous… sometimes with very little notice. We’ve already seen this happen.
That raises an awkward but necessary question: what happens if your heat pump is only affordable because a special tariff exists?
Heating demand peaks in winter. Winter coincides with high national demand. High demand usually means higher prices. That basic reality doesn’t disappear just because a tariff spreadsheet looks good in summer.
Batteries bring their own compromises. They require significant upfront investment, lose energy every time they cycle, and degrade over time. They can soften the edges of a poorly optimised system, but they can’t fix it. Efficiency is the only long-term protection homeowners have.
A heat pump running at a low flow temperature, matched correctly to the property’s heat loss, doesn’t rely on clever tariffs to survive. It’s resilient. It copes when prices rise. It doesn’t panic when products change. And it gives homeowners options rather than locking them into workarounds.
This matters just as much for existing owners as for people still deciding. If you already have a heat pump, your bills aren’t just costs, they’re data. They can tell you whether your system is fundamentally sound or quietly struggling. If you’re considering one, the questions you ask before signing a contract will matter far more than the brand badge on the unit.
This isn’t about being anti-heat pump. It’s about being honest. Heat pumps are excellent technology, but only when treated as engineered systems, not lifestyle products propped up by temporary pricing structures.
The video below explores this in detail, using real numbers, real systems, and real homeowner experiences. Once you’ve watched it, the discussion continues in the Renewable Heating Hub forums, where homeowners compare notes, challenge assumptions and learn from each other.
