think of to try and get an answer. I live in Houston, and for the past 3 or 4 days it has been really cold for us here...almost freezing. I don't know if this has anything to do with what is going on or not. When I turn on my hot water faucet in the bathroom sink, even before the water turns hot, I start hearing a knocking sound behind the mirror that is behind the sink. What is causing this and should I be concerned. Thanks.
2007-01-18 16:08:04 · 6 answers · asked by Corona 5 in Home & Garden ➔ Other - Home & Garden
It does not do it with the hot water and it doesn't do it with the water in the shower or in the kitchen. Also, the freezing weather ended yesterday and we are just back to regular cold for Houston.
2007-01-18 16:09:29 · update #1
Sorry, I meant it does not do it with the cold side.
2007-01-18 16:10:05 · update #2
No need for concern! It is what is commonly called water hammer. You could try and turn the valve off, that is right above your water heater. Once it is off, open all the hot faucets in the house, and leave open, until no water comes out. now close all the faucets, and turn the valve above the water heater, back on. There should be some pipes in your system, called air chambers. These pipes trap air in them, and allow a "cushion" of air, which allows the water room to expand. When these pipes fill up with water, you will experience pipes moving, or knocking, in the walls. There are some mechanical devices, that can be purchased, and installed, which also eliminate this problem. I live in Pasadena, Tx., and work all over the greater Houston area. I own my own company, so if you like, I would be willing to evaluate your plumbing system, and make a recommendation, as to what needs to be done. I hope this helps! Have a good day!
2007-01-18 17:02:44 · answer #1 · answered by poppyman54 5 · 0⤊ 0⤋
I suspect that your hot water tank is generating bubbles of air when the incoming very cold water mixes with hot water already in the tank, setting the stage for rapid pressure changes in the hot water lines in your house. When you open the hot water faucet in the bathroom, some of the pressure is relieved as the water flows, but the remaining pressure reverberates thru the system until it equalizes.
The cold water line normally won't have this problem because all the lines are the same temperature.
Two things could be done: fasten the pipes inside the wall securely to the wall studs, and install a water hammer control device. The latter device acts to dampen and absorb any pressure pulses in the water line with an internal spring and prevent them from hammering the pipes.
You might also check to see whether the washer inside the faucet is worn out and needs replacement. A thin or worn washer might vibrate when you open and close the faucet.
2007-01-19 01:05:30 · answer #2 · answered by Tom-SJ 6 · 0⤊ 0⤋
In hearing what you say I would think that the water in the hot water line is colder than normal due to the colder weather you have been experiencing. So when you turn the hot water on the hot water from the hot water tank has to displace the water in the hot water line between the tank and the bathroom. There is now a greater temperature differential between the water in the line and the hot water from the tank, so the copper line that carries the water will expand more "grow in length" and cause the noise as it grows until the line is at a constant hot temperature. The line sounds like it is not fastened very well in the wall thus the line has room to vibrate as it grows. I would think that is all the problem you have, really nothing to worry about just a little noise in the cold weather. Hope this is it....Cheers!
2007-01-19 00:20:35 · answer #3 · answered by Steiner 6 · 1⤊ 1⤋
It could be someone trapped, no I am just kidding! Relax! it is called water hammer. The pressure in the pipes causes the loose pipe in the wall to vibrate and hammer. If the water is extremely hot, turning down the temp might help the vibration. Other wise, it is annoying but, not dangerous
2007-01-19 00:15:32 · answer #4 · answered by T C 6 · 1⤊ 1⤋
There may be ice in the line somewhere.
TUrn the water on for 15 minutes or so in the hose. The cold water is warmer than freezing and will melt any ice in the line.
2007-01-19 00:16:31 · answer #5 · answered by Anonymous · 1⤊ 1⤋
the pipes are expanding as they heat up. that makes the knocking sound
2007-01-19 00:14:41 · answer #6 · answered by earthgirl766 3 · 1⤊ 1⤋