ᐅ Air in cold water pipe: Loud noises despite normal water pressure?
Created on: 9 Dec 2025 12:02
H
holp4444
Hello everyone,
For several weeks now, we have been experiencing air in the cold water pipe, which causes loud noises when water is running (for example, when the flush tank fills, the washing machine draws water, or when washing hands). You can also notice the water turning briefly cloudy at the faucet, indicating air in the system.
We live on the upper floors (1st and 2nd floor) of a two-family house built in 2004.
When I stand in the basement near the supply line or close to the expansion tank (refix DD 12) while water is running, I can clearly hear the noises.
Since I could not find any leaks or dripping pipes and the pressure seems fine (around 5.5 bar), I wanted to ask here if you can suggest possible causes?
I just pressed the valve on the expansion tank again, and only air came out...
I have attached a few photos. Could it be that air is entering the system through a defective component in the pipe run?
I hope enough is visible despite the poor lighting conditions.
For several weeks now, we have been experiencing air in the cold water pipe, which causes loud noises when water is running (for example, when the flush tank fills, the washing machine draws water, or when washing hands). You can also notice the water turning briefly cloudy at the faucet, indicating air in the system.
We live on the upper floors (1st and 2nd floor) of a two-family house built in 2004.
When I stand in the basement near the supply line or close to the expansion tank (refix DD 12) while water is running, I can clearly hear the noises.
Since I could not find any leaks or dripping pipes and the pressure seems fine (around 5.5 bar), I wanted to ask here if you can suggest possible causes?
I just pressed the valve on the expansion tank again, and only air came out...
I have attached a few photos. Could it be that air is entering the system through a defective component in the pipe run?
I hope enough is visible despite the poor lighting conditions.
J
Jesse Custer23 Dec 2025 13:52It took us years...
When the tank eventually empties, the excess pressure simply releases water from the safety valve. If this valve fails or is not properly sized, the hot water storage tank will bulge significantly. Flooding risk.
The maximum pressure the tank can withstand is indicated on its nameplate.
The maximum pressure the tank can withstand is indicated on its nameplate.
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