Hello,
I am living in a 10 year old house with gas central heating. Over the past 6 weeks I am hearing an intermittent loud (metallic?) banging or rumbling noise from the loft. It lasts about 10 mins with no obvious pattern.
Today it happened again and I noticed the overflow pipe was gushing with water (not sure if this was from hot water feed, or cold water feed tank as it all stopped by the time I could get into the loft!!!). The loud noise was definately coming from the direction of the hot/cold water tanks and was possibly caused by the water rushing though the plastic overflow pipes which rattle a bit. The central heating was on and there was also faint metallic 'tinkle' sound coming from the downstairs radiator.
I went into the loft, noise has stopped, and noticed the cold tank was full, and the hot water feed tank was also full and very warm to the touch.
Heating system seems to work fine.
Any ideas?! Your help will be much appreciated so I can understand the problem before calling out a plumber.