Hi there wonder if anyone can help. We have an Ideal Classic boiler, non-condensing (not that new). All has been fine since we moved in a few months ago but recently there have been very loud noises coming from the area from the pump in the upstairs airing cupboard. The pump is set on Level 2. The noise is a bit like trapped air forcing its way through the pipe, or very high pressure water going through and it does seem to be centred on the pump (I know it might not be really, though, and acoustics can play tricks). It's loud enough to make you think the whole thing is about to explode! What I'm wondering why it would suddenly start making a noise now when it fine for the last few months? We haven't changed any of the heating settings, other than turning the thermostat in the hallway. To save on energy we don't have all the radiators in the housr on. 3 of them have the valve left in the closed postion. Is this a bad idea and is it anything to do with the noise? If not how can I stop the noise? Should I turn the pump switch down to Level 1? Any advice appreciated.