Having been up into the loft there is water in the tank, sorry I'm a bit of a novice at this!
If it helps, the noise seems to come from either the boiler itself or the pipes coming out of the boiler, I can't work out which.
I read that maybe the boiler pump needs bleeding? ANyone know...
Yesterday I bled one of my radiators as it wasn't getting hot at the top. However since I've done that I now get a humming/whistling/annoying tone from my central heating boiler.
When the boiler kicks in after about 5 minutes it starts and is consistenet and quite loud.
I can only think...