I have a slight problem with my hot water... I hear a loud rushing sound from my hot water lines even when hot water is not being used. I turned the cold water feed off to the heater and the noise stopped. I have a crawl space under my house and I went under to look for leaks and didn't see anything. It's all soft copper under the house so there are no fittings or joints that would leak. There is no visible sign of a leak anywhere... At first I thought it could be cavitation but the cold water lines aren't making any noise and the sound is still heard when all hot water fixtures are off. I am a union plumber in training and I cannot figure it out. I don't have any experience in troubleshooting residential problems so anything would help...

Hey Zach,
First off let's check for a hidden leak. To check to see if you have a hidden leak first shut down everything in the house, no flush, no drinks of water, and if you are on a meter go out and check the little pointer in the gage. It should not move or creep. If it does you have a leak. If you're on a pump then check the pressure gage after the pump builds up to pressure and shuts off. The gage should not fall and the pump come back on. If so then you have a leak and let me know. Hope this helps and thank you for rating my reply, Tom

It can be the smallest pin-hole type leak producing fine mist, not even a drip. However, it is very audible when noise pollution is down. Take a flash light and start investigating. Look for wetness in crawl space, around baseboards, inside cabinets, feel if carpet is wet along side of walls... etc. Let us know what you've found out...

Hey thanks for the input guys, it was a leak in the hot water. I found it before I got a chance to come back on here, but yeah it was a leak. In a very unusual place too, there's a 1/2 inch. Soft copper line about 50 feet long buried between my house and the garage that goes to a laundry sink the washer. Right in the middle of the grass there was a warm puddle and upon further investigation I found the leak. It looked as though the copper had been kinked when installed and over the 30 years it had been in use a hole had finally worn through. A couple of couplings later and problem solved. Thanks for the help though guys.

We're glad you problem was a small one. Let us know if you need us in the future. Regards, Tom