Heat Pump Cycles & Performance7 / 17
Heating Modes: Heating, Defrost, Electric Backup
Heating-only, heating + cooling (reversible), defrost cycles, auxiliary heating.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
Whether a heat pump beats a gas boiler is not a matter of opinion; it is four numbers: the electricity price, the gas price, the boiler's efficiency and the heat pump's seasonal COP. This lesson runs that comparison honestly at the platform's reference prices, shows where the breakeven sits, and covers the operating modes and design choices that decide which side of it a real installation lands on.
In this lesson
- 01The cost-per-kWh-of-heat comparison
- 02What decides the real SCOP: flow temperature
- 03Modes and configurations
- 04Sources and further reading