Im not sure if you would call it a whistle or a hum, or somewhere inbetween. Im imagining there is some air in the system but i havent a clue. We had it serviced about 4 months ago by a Corgi registered engineer and he identified some problems including a sticky diverter valve and a slight leak...
Hi all,
I am the unlucky owner of a Super 90 boiler which has given me all manner of headaches. We have recently had the TRV's changed on the radiators and now our boiler seems to be making a loud humming noise when the hot water is on. The flame looks fine and is blue and it sounds fine when...