Plumbing help - Noise in loft

Toonsy

Hi

So just recently I've noticed a groaning sound coming from the loft. It happens intermittently and I'm in the process of isolating things.

So what will happen is this noise will happen then I'll hear water filling into toilet for a brief moment. If I flush the toilet or run some water off it cures it or seems to temporarily. I've also had the heating on these past few days which has obviously been off all summer so perhaps it's something to do with that?

Ultimately I've isolated the sound to the loft so need to get up there but some ideas of what to be looking at would be handy. There's nothing coming out of the overflow pipes.

-taff

Sounds like an airlock somewhere....

Toonsy

I thought that.... but tgen I thought maybe the ball valve in the cold water tank may be coming to the end of its life?

It onky happens when the heating/hot water is on but it stopped when I turned the mains off and ran some water off ensuring the tank didn't fill so I'll look at that later.