This was a very big system comprising 27 radiators and 3 heated towel rails over 3 floors and spread over 4 thermostatically controlled heating zones. It represented the equivalent of 4 normal houses. The Engineer was not phased by this daunting task which was carried out in a highly professional manner without fuss and minimal disturbance during the 2 days it took to complete. We picked PDL at random from the internet and we regard ourselves as very lucky to have discovered such an exceptional craftsman.