Home / Advice Centre / Efficiency & Running Costs
TOPIC HUB 08 · EFFICIENCY & RUNNING COSTS
Heat Pump Efficiency & Running Costs
Running costs depend on more than the heat pump’s rated efficiency. Building heat demand, flow temperature, electricity tariff and how well the system is set up all combine to determine what a heat pump actually costs to run.
- Topic hub
- Updated August 2026
- By Phil · Heat Loss Hub
COST DEPENDS ON MORE THAN THE HEAT PUMP
Two identical heat pumps in two different houses can have very different running costs. The building’s heat loss, the flow temperature the system runs at, and the household’s electricity tariff all matter as much as the heat pump’s own efficiency rating.
COP and SCOP: what the numbers actually mean
COP is a snapshot efficiency figure measured at a specific outside and flow temperature. SCOP averages performance across a full heating season. Neither figure tells you what your specific home will achieve — that depends on how the system is actually designed and run.
Flow temperature is the biggest lever on running costs
Running the same heat pump at a lower flow temperature can meaningfully improve efficiency. This is one of the main reasons emitter sizing and flow temperature strategy matter as much as the heat pump model itself.
Electricity tariff changes the answer
A heat pump on a standard tariff and the same heat pump on a time-of-use or heat-pump-specific tariff can have noticeably different running costs, even with identical performance. Tariff comparisons should always be checked alongside efficiency comparisons.
Heat pump vs oil and LPG running costs
Off-gas-grid properties on oil or LPG are often where heat pumps compare most favourably, since these fuels tend to cost more per kWh than mains gas. The comparison still depends on the property’s heat loss and the design flow temperature achieved.
Weather compensation and efficient operation
A system that automatically reduces flow temperature as the weather warms will generally run more efficiently over a season than one held at a single fixed temperature all winter. Getting the heating curve right is often a bigger factor than people expect.
The best way to reduce running costs is usually design, not equipment shopping. Getting the flow temperature, emitters and controls right typically has more impact than chasing a slightly higher-rated heat pump.
Continue exploring efficiency & running costs
CONTENTS
WANT LOWER RUNNING COSTS?
Get an independent design review focused on efficiency.
WANT TO KNOW WHAT YOUR PROPERTY WOULD ACTUALLY COST TO RUN?
Running costs come from design decisions, not luck.
Heat Loss Hub can review the design decisions that drive running costs — heat loss, flow temperature and controls — independently of any equipment sale.