Hot water cylinder/pipes making whining noise?

Question

There is this really loud whining/moaning noise coming from my hot water cylinder and then resonating into the pipes. The noise stops if I turn off the hot water at the cylinder, or if I turn on a hot water tap in the house - but otherwise the noise is constantly there.

I can't afford to get in a plumber, so any suggestions as to what might be the problem would be greatly appreciated.

Cheers!

Answer 1

sounds like you may need a water hammer, or check to see if there is an in line valve somewhere that is not completely open. A plumber can install a hammer but you can check the valves.

Answer 2

A "thumping" noise may be experienced whenever a hot tap is turned off suddenly. This only occurs if a non-return valve is installed. The sudden stopping of the water flow at the hot tap causes a small "energy wave" to travel back down the water pipe. This "energy wave" generally diminishes but if a non-return valve is installed, the energy comes to an abrupt halt causing a "thump" to be heard. This is a form of water hammer.

A continuing light vibration or whining noise may be heard if there is a defective tap washer in the tap housing. Replace the tap washer.

A continual tapping or knocking noise may be heard when a tap is running. This is water hammer. It occurs when long runs of hot water pipe are not adequately fastened inside the wall, ceiling or floor cavities, and results from the pipe vibrating against a wall, ceiling or floor cavity as the water passes through the pipe causing it to resonate. This is overcome by securing the hot water pipe, to prevent movement.

If an electric water heater is installed and noise is evident only during the heat-up cycle, check for mineral build up on the heating element and check the quality of the water supply for sludge. Clean the heating element or drain sludge from the water heater if required.

If a noise is evident only when water is flowing through the water heater, and if it's not water hammer, then check for restrictions in the pipe work or for faulty valves. It may be necessary to install a pressure limiting valve if the water pressure is excessive (above 700kPa).

Answer 3

the water is turning into steam from being overheated. i'm not to sure if your dealing with a whole house water heater or a point of use small water heater but try to locate the thermostat and turn it down slightly also make sure you have a safety pressure relief valve somewhere on the tank. I've also known water heaters to moan and groan when they accumulate large amounts of calcium deposits in the bottom of the tank. If there is a low point drain turn the gas or electricity off to the unit and see if you have alot of sediment coming out of the drain when opened

Answer 4

Hi,

it might be a too high temperature of the water causing small gas explosions in the water (same as you see with boiling water).

If there is a drain for the gas (e.g. an overpressure valve) you should activate it (it might be stuck because if lime deposit).

You should also verify the temperature level: higher temperature gives more gas evaporation. 60degr C should be the max