Installed a Vaillant 630 boiler. Simon is is courteous, thorough, knowledgeable, experienced and works very hard. During the assessment he stayed a bit longer and drained the old boiler which was leaking everywhere without us asking - he just offered! All questions we asked beforehand around different makes of boiler and size were answered simply and with minimal technical jargon. He kept us informed at all times and installed the boiler in a day so we had our central heating back the same day he turned up - he stayed longer to do this. No surprises, price paid was as quoted and he cleared up at the end of the day. Cannot recommend highly enough - such lovely bloke!