What Size Heat Pump Do I Need?

Boiler size is not the answer

One of the most common mistakes is assuming the new heat pump should match the old boiler. Heat pump sizing should come from the heat loss of the home, not from legacy equipment.

That is why the estimate tool can give a useful first kW guide, but the survey is what confirms the final answer properly.

What determines the right size

The final size depends on room-by-room heat demand, hot water requirements, emitter performance and how the system is designed to run in real winter conditions.

Getting that right matters. A system that is too big or too small can both create problems for comfort, efficiency and running costs.

• Room-by-room heat loss calculations
• Emitter and controls strategy
• Hot water and household usage patterns