Air source heat pumps work at lower temperatures compared to traditional boilers. This means they take longer to warm up and heat your home.
They are designed to deliver gentle, consistent heating over longer periods, so it usually works out cheaper to keep them on all day. Try setting your thermostat to a constant temperature between 18-21°C during the cold season. This can reduce the amount of electricity needed to keep your home at a comfortable temperature and save you money.
Your external unit needs good airflow to work efficiently. Keep the vents clear.