Overall verdict, excellent. The ordering process is simple giving you a fixed price, simple as that. We opted to pay outright by card, but finance is available if required. Our old boiler was at least 25 years old (we inherited it when we bought the house) and needed changing. The online booking process offered installation slots just 2 days away, although we opted for one about a week away. On the day of the install, Jaime the engineer arrived as expected in the morning and set about the installation. Nothing was too much trouble, his work is very neat and he tidied up the the mess and packaging when he had finished. Unfortunately we had a problem with our gas supply pipe which meant that Jaime couldn't commission the boiler that day, although he tried! We had to have Cadent out to fix our supply pipe which took all the next day (Friday). Jaime returned on Saturday to commission the system. The supply problem was just one of those things and couldn't have been foreseen. The boiler itself is a Viessmann Vitodens 35Kw model and is performing perfectly. I would recommend heatable without any hesitation