They are still around. They upgraded my neighbours' heating. They added a pipe and a valve to make topping up easier. A radio thermostat. A motorized valve instead of the manual summer/winter diverter valve. They also replaced the back boiler with the same which I was less keen to do which is why they got the job. In fact come to think of it their house (mine too for that matter) is one of the few houses where a non-condensing exemption could be used.