loud noise from boiler/water tank?

malima

Hi guys,
Can someone please help me?
I think there is something wrong with my boiler, or water tank, for the pass 3 days, every time anyone uses the hot water tap from the bathroom/en-suite or kitchen, my house sounds as though there is a train running through it,(the first time it happened, it scared the life out of my sons).

I phoned the Scottish Gas Homecare, and the girl said to bleed all the radiators, i did that , but it is still making the noise, do i need to wait for a few days first, to let the boiler settle?
She said it sounded like trapped air.

Thanks for anyone's help.
malima

The noise is still there, even though the taps are'nt on?!
It's noisy for about 4 mins.

a&akay

If you've got a cold feed tank to your hot water system, it could be water hammer as the valve lets in cold to replace the hot you have used (this can take 4 mins). If you can reach the ball in this tank, try pressing it down. If the noise stops it is water hammer and you need to try the solutions recommended by Googling 'water hammer'.

morganb

We have this problem too, and apparently we need a new equilibrium ball valve.