We first used GRT Heating and Gas Services three years ago to install a new Wiessman Boiler and replace all radiators. All annual boiler services have been carried out by David. We had a new bathroom installed last year (by others) causing the radiators not to reach full heat. David quickly diagnosed the issue after carryout some tests, he modified the heating circuits and now have the existing pump to maintain the boiler/cylinder and by use of a header and additional pump flows round the radiator circuits has been improved such that all our radiators now exceptionally hot throughout the house. David was, as usual, professional, carried out a high standard of install, was polite and tidied up after himself with absolutely no fuss. We have booked David for next year’s boiler service.