If you've recently replaced your gas boiler with a heat pump, adjusting your heating habits can make a big difference in how efficiently and affordably the system runs. Unlike gas boilers, which generate heat directly, heat pumps work by extracting heat from the air or ground and transferring it indoors. They generally perform best when they operate continuously at lower temperatures rather than cycling on and off. Phil Steele, a future technologies evangelist at Octopus Energy, warns against making large changes to the thermostat, such as raising it several degrees in the evening and then lowering it again. Instead, making smaller adjustments and following a thoughtful schedule can help avoid the inefficiency of constantly reheating a cold home. Turning the heating off entirely when leaving the house for a few hours can cause the home to cool down significantly, which then requires the heat pump to work harder to bring the temperature back up. A better approach is to reduce the thermostat slightly rather than turning the system off, especially in colder weather. Programming the heat pump to start warming the house earlier in the morning, instead of waiting for an immediate burst of heat upon waking, can also improve efficiency. The flow temperature, or the temperature of the water leaving the heat pump and moving through the heating system, is a key setting. Heat pumps can run more efficiently at lower flow temperatures, but this setting shouldn't be reduced too much without considering factors like the home's heat loss and the size of the radiators. If the flow temperature is consistently high, it may be worth consulting the installer to optimize the system or adjust weather-compensation settings. Radiators may feel cooler than those from a boiler, but this doesn't necessarily mean there's a problem. If the heat pump also heats a hot-water cylinder, scheduling when the hot water is produced is important. Heat pumps typically focus on either space heating or hot water at any given time, so heating the cylinder when the house is also being warmed can temporarily disrupt space heating. Scheduling the hot-water tank to heat during off-peak hours, such as between midnight and 3am and again from midday to 3pm, can help maintain comfort while using energy more efficiently. On a time-of-use electricity tariff, heating water during cheaper periods can further reduce running costs. Optimizing a heat pump isn't just about using less electricity, but also about choosing when to use it. For example, Octopus Energy's Cosy tariff offers cheaper electricity during specific periods of the day, allowing heat-pump owners to warm their homes or heat their hot-water cylinders when electricity is more affordable. This can lead to lower overall costs even if slightly more electricity is used during these cheaper times. Finally, it's important not to worry about a single day's efficiency. Most heat pumps report a coefficient of performance (COP), which can vary depending on the weather and other conditions. A COP of around 2.8 during colder winter months compared to 3.5 in the summer is normal. The seasonal coefficient of performance (SCOP), which averages performance over a longer period, provides a more accurate measure of the system's efficiency than a single day's figure.