I just moved i my "new" home and noticed that my boiler (Heat 60) makes a little banging noise on ignition. The ignition sequence starts like this: pump and fun running then, ticking noise followed by a fssssss noise(gas) then bang noise which moves the the surface of the cover a bit. Otherwise the boiler runs fine and seems very powerful as it heats my 4 bed house in just minutes. The noise is just a bit annoying thats all....is it normal or something wrong? also noticed the other day that the boiler war running without the "burner on" led lit and the radiators were not warm. I switched it off and on and its been running ok again...just the bang noice at ignition. any ideas????