The cost of installing a heat pump system varies based on factors such as the type of heat pump, system capacity, and installation requirements. On average, installation costs can range from a few thousand to several thousand pounds. The operational cost, or running cost, depends on factors like energy efficiency, local climate, and usage patterns. While initial installation costs may seem significant, the long-term energy savings and potential government incentives can contribute to cost-effectiveness over time. It's recommended to obtain quotes from reputable installers to get accurate figures tailored to your specific needs and location.