Just a short update. No problems to date with our system, and running costs still match what we would have had with a gas boiler. For those interested in installing one here is ann article from the Guardian that answer a lot of questions I get asked.

Are heat pumps the future or just a lot of hot air?
https://www.theguardian.com/environment/2024/sep/28/heat-pumps-future-hot-air-labour-home-upgrade

On the question about will it keep my house warm, the answer is yes if it is specified properly. It won’t be significantly different to run compared with a gas boiler on standard energy rates, if it is installed properly. In time we will all need to get rid of gas boilers, so make your choice when you need a change of boiler and make sure you find a reputable installer that guarantees it will work.