After installing a new dish washer last night, I noticed that there is a high pitched squeal coming from the water line when the washer is running. Can someone pleas tell me what is causing this? I suspect maybe air in the line or restricted flow.

Does the squeal change in pitch while the washer is filling? I suspect that you fill valve is not fully closing. Back to you.

Ballengerb1,

It does not change pitch but it does get louder and softer throughout the course of a wash cycle. If the valve is not closing fully, could this be due to high water pressure... or just a faulty valve?

Your water pressure should be between 40 and 60 psi, do you know what it actually is on your line? I guessing it's the valve since the problem started with a new installation. There could be a spec of debris inside the valve that allows a trickle of water to keep passing. Some machines have valves that can be opening, cleaned while others do not. You'll have to check right in front where the water line connects, that's the valve, do you see any screws or caps that can be removed?