Called on Monday to say had moved into the new place , where we knew the boiler had been condemned in 2015 according to the seller , (had had a visit to give quote ) work was started on Friday and finished on Monday (had been told 3 working days not Inc weekends ) , was shown how to turn Emerson tank on so was not left without hot water , which was more than we had when started , excellent communication, clean , professional gentlemen . Would definitely recommend gas safe to everyone , I know who I will be calling if I ever have any other problem .