# Hot water pipe making scary noises - Please help!!!



## Sarah24 (Feb 26, 2008)

Today when I finished my shower and went to turn the hot water off it suddenly make a weird loud creaky noise. I think the pipe might have actually been moving behind the wall - at least that's what it sounded like. I tried to turn it on again to see what was going on, but it made that noise again and I stopped right away. Now about an hour later I tried again, but the noise stopped. We've been having weird problems with the shower for awhile now. We sometimes get sudden bursts of water pressure in the shower. So now I'm freaking out thinking the pipes about to explode. Also it might be relevant to mention that I live in a very cold state - it's about -2 degrees, so I'm not sure if that has anything to do with it, but I'd thought I'd mention it just in case. However, my pipes are fully winterized and I still leave the kitchen faucet drip just in case. So.... if anyone has idea what this could possibly be please leave a comment.


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## micromind (Mar 9, 2008)

How hot is the water? Any possibility is could be boiling? Remember, the higher the elevation, the lower the boiling point. 

What type of valve? How old is the plumbing? 

It sounds like possibly water hammer, that can certainly seem like the pipes are going to explode. 

Sorry for all the questions, but a bit more info would be helpful. 

Rob


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## Nestor_Kelebay (Jun 17, 2008)

Sarah:

No, your water heater has a "pressure and temperature relief valve" on it that opens if the thermostat malfunctions and the heater keeps heating the water well past it's set temperature. The P&T relief valve is the thing near the top of the heater with the pipe coming out of it that goes down close to the floor. Typically, that P&T relief valve will open at 150 psi or 200 deg. F, whichever comes first. Also, your water supply piping is typically at a pressure of 40 to 80 psi, and so the boiling point of the pressurized water in the piping would be higher than 212 deg. F.



Sarah24 said:


> Today when I finished my shower and went to turn the hot water off it suddenly make a weird loud creaky noise. I think the pipe might have actually been moving behind the wall - at least that's what it sounded like. I tried to turn it on again to see what was going on, but it made that noise again and I stopped right away.


That MIGHT be water hammer, but that noise doesn't happen when you OPEN the hot water valve... water hammer only happens when you close a valve, and the faster the water is running and the faster you close the valve, the more magnificent the water hammer will be. That's because water is heavy and it has considerable momentum when it's flowing through a pipe. If you suddenly stop the flow of the water (by closing a valve), then the momentum of that water is transfered to the pipe, and the whole pipe lurches forward and back if it can. It's supposed to be anchored with clips every so often to prevent it from moving, but builder's don't always put those clips in as often as they should.

But, I kinda doubt it's got anything to do with water hammer because water hammer doesn't happen when you OPEN a valve, only when you close the valve.

What you're probably dealing with is just a loose washer on the hot cartridge in your shower valve. You see, when the screw holding a rubber washer in place is loose, then the water pressure in the piping can get behind the washer and slam it forward, and the water pressure in the piping can then slam it backward again so quickly that it can sound like anything from a cat squeeling to the Queen Mary's fog horn. This will ONLY happen when the faucet is just opening or just closing; it won't happen once the faucet is open more than just a bit because then the washer is further from the seat and can't stop the flow of water, and it's that rapid starting and stopping of the water flow that causes the noise and vibration.

(I suppose it could happen even when the faucet was wide open if the screw holding the washer in place was so loose it was about to fall out, but if this is the first time you've heard the noise, my bet is that the screw is just a little loose and not about to fall out.)



> Now about an hour later I tried again, but the noise stopped.


Which also confirms to me that it's probably a loose washer. That loud noise requires that the washer move forward and backward rapidly, and it's the water pressure getting behind the washer that causes that. But, it doesn't always happen. Some times the water pressure doesn't move the washer forward at the time you're opening or closing the faucet, and the faucet behaves.



> We've been having weird problems with the shower for awhile now. We sometimes get sudden bursts of water pressure in the shower.


I was the one who suggested scale build-up in your "Insane water pressure in shower" thread. Did you take a listen to that water heater while the shower is running to see if the heater is also making noises that coincide with those high pressure episodes?



> So now I'm freaking out thinking the pipes about to explode. Also it might be relevant to mention that I live in a very cold state - it's about -2 degrees, so I'm not sure if that has anything to do with it, but I'd thought I'd mention it just in case. However, my pipes are fully winterized and I still leave the kitchen faucet drip just in case. So.... if anyone has idea what this could possibly be please leave a comment.


Temperature doesn't cause any problems at all unless the pipes freeze solid.

Try getting the hot water in the shower to make that noise again, and then while it's making that noise, gradually open the hot water more to see if the noise stops as the washer is moved further from the seat so that it can no longer cover the seat and stop the water flow. If the noise goes away as the hot faucet is opened, then you know the problem is a loose washer.


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## Sarah24 (Feb 26, 2008)

I have been turning on the shower off and on for the last few hours and it doesn't seem to be making that noise anymore. I'm not saying I think it's fixed - it's just not doing it right now I guess. I should of also mentioned that this is a mobile home I'm working on for resale and it's quite old, so that means old pipes. I wouldn't be surprised if there's a million and one problems with the plumbing. Also, the water heater is directly behind the shower wall that has the shower head on it, and it's a really old water heater. I think it's from 1983. I considered replacing it, but I never had any problems with it, so I just let it be. And I want to quick say I've heard on tv and in movies the stereotypical "knocking pipes" sound and that is not what I'm hearing. It's a screeching, creaking, loud noise. I could have my husband get to the water heater and see if there's proper clamps to hold pipes in place just to be sure. But as far as the "loose washer on the hot cartridge in your shower valve" - how do I get to that to see if that's the problem? Also this is completely unrelated, but when I turn the shower on, some water still comes out the faucet and not just a little. About a quarter of the water still comes out. If I replace the faucet will that fix the problem?


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## Nestor_Kelebay (Jun 17, 2008)

Sarah24 said:


> But as far as the "loose washer on the hot cartridge in your shower valve" - how do I get to that to see if that's the problem? Also this is completely unrelated, but when I turn the shower on, some water still comes out the faucet and not just a little. About a quarter of the water still comes out. If I replace the faucet will that fix the problem?


Find out who made the faucet (Moen, Waltec, Crane, Delta, etc.) and then phone around to the order desks of the major plumbing wholesalers in your area to find out who the sales rep or sales agency for that manufacturer is in your area. That sales rep or agent will have the original literature that came with your faucet on file, but you will have to send him a picture of your faucet so he can identify the right one in his book, and he can photocopy the original literature for you. It should include an exploded diagram of the faucet including part numbers for the individual parts. If you show that diagram to any of the people working in a hardware store plumbing aisle, they should be able to tell how to replace a loose washer just from looking at the diagram.

Water "saver" products can often be "water wasters". For example, when water conservation first became popular, a number of faucet manufacturers started making "flow restrictors" for their shower heads to save on water. The problem is that the flow restrictor would simply reduce the water flow into the shower head. Since the holes in the shower head didn't change, the result was that the water flow through those holes wasn't fast enough to "spray" water onto you, it only "spilled" water onto you.

And, not all diverter spouts are created equal. You can buy a diverter spout that's made in China at any hardware store, and it'll leak half the water out of the spout and only half goes to the shower head. If you then put a "water saver" shower head on, it just causes more water to be wasted out the spout. I own a small apartment block, and my tenants like decent showers, but I don't like to pay for them using more water than necessary. I've found that I get the best results with this shower head:

The Niagara Model # N2130 shower head, and:

For "slip-on" type bathtub spouts:
The Moen Model # 3931 diverter spout, or

For "screw on" type bathtub spouts:
The Moen Model # 3926 diverter spout.

You need to order these from any plumbing wholesaler or retailer that sells Moen in your area. Both will leak NO water when the diverter is raised, thereby diverting the water flow to the shower head.


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