I had the Eco4 grant and it was challenging for about 4 months while work was being done, but was worth it. I know a few others who had Eco4 grant too and their experiences were similar to mine. Really check the feedback of companies before you select who to go with. Mine had terrible reviews but I didn’t realise until they were here. Leaks, pipework installed incorrectly, electricians who had never installed an air source heat pump before and missed wired it, then blagged that it was all fine. They photographed each bit of work completed so they could get paid. My opinions were irrelevant as I wasn’t paying them. Eventually it was all sorted out by an approved heat pump engineer. This was only happened after the energy company, sponsoring the Eco4 contractor, had sent out an independent inspector who failed the installation. The approved heating engineer had to fix the system by re plumbing and re wiring, adding frost stats and magnetic filter. Got there in the end and it’s fantastic having a warm home.