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rumbling pipes and leaking pressure relief valve

10K views 21 replies 4 participants last post by  Homerepairguy 
#1 · (Edited)
I have a couple of issues that may or may not be related. I have seen bits and pieces of similar issues, but not sure if they apply to mine. I had the cold water shut off to my kitchen sink for about 3 0r 4 weeks while I waited on the new single hot and cold valve. The pipes inside the walls starting vibrating shortly after I had cut off the cold water shut off valve in the kitchen. I finally got the part and replaced the faucet handle. My pipes continue to make the rumbling sounds, and turning on the water in one of the bathrooms or kitchen temporarily stops it. My water heater is a GE 80 gallon tank and it is about 5 or 6 yrs old. I thought maybe tripping the pressure relief valve would stop the vibrating, but it didn't, and now the pressure relief valve wont stop dripping unless I cut off the main. Is there a relation to theses two issues? I lifted the relief valve up an down several times thinking maybe it was sticking like I have read happens, but it did not fix it. Should I try tapping on the outside of that valve with a rubber mallet in case the plunger is just stuck or what do you recommend? Not that this is necessarily related, but I had just replaced a grey PVC elbow going to my outside spicket with a brass elbow right before I replaced the kitchen faucet valve. The water heater has never gave me any problem before this. I also turned down the temp on the water heater from the factory 125 deg setting probably down to 110 or so. It does not have a reading there.
 
#2 · (Edited)
I had the cold water shut off to my kitchen sink for about 3 0r 4 weeks while I waited on the new single hot and cold valve. The pipes inside the walls starting vibrating shortly after I had cut off the cold water shut off valve in the kitchen.
When you shut off the cold water to your kitchen sink using the valve under the sink, was the water dripping out of the faucet? If so, that could have caused the rumbling sound due to vibrations in the valve seal.

My water heater is a GE 80 gallon tank and it is about 5 or 6 yrs old. I thought maybe tripping the pressure relief valve would stop the vibrating, but it didn't, and now the pressure relief valve wont stop dripping unless I cut off the main. Is there a relation to theses two issues?
Since you shut off the "cold" water to your kitchen sink, what led you to believe that the heater (hot water) was causing the problem? Since the pressure relief valve on your heater won't stop dripping now, it may be defective. Anyway, check your home's water pressure. Suggest 60 psi or less. You can also try adjusting the pressure regulator to move the internal parts to see if the rumbling stops.

Try turning off every valve feeding your toilets and see if the rumbling stops. If it does, one of your toilet's fill valve is probably leaking and may be causing the noise.

Is any faucet leaking?

See if there's a slow leak anywhere in your plumbing by checking your city's water meter and see if the water movement indicator is spinning.
..... 1. To determine which indicator is for water movement, turn on any faucet and look at the meter. The indicator that's spinning like crazy will be the water movement indicator.
..... 2. Shut off every faucet. Note the position of the water movement indicator.
..... 3. About 30 minutes later, check the water movement indicator again. If it moved, you have a slow leak somewhere. Probably through a valve and vibrating the valve seal.

Just some thoughts,
HRG
 
#3 ·
Rumbling sound could be water hammer. Does it happen when the water is shut off or just as you or just after you shut a water valve to a sink, shower, or toilet finishes filling?
You may need an expansion tank to prevent your TP valve from leaking. Might want to get a pressure gauge from big box store and get a reading on your home's water pressure. They screw onto a hose connection just like a garden hose and they've a little dial that shows the pressure.
 
#4 ·
Your water heater pressure & temperature relief valve may have gotten a little clogged with sediment that it does not close completely.

Water expands slightly when heated. If there is a backflow preventer where your main water pipe enters the house and you don't have any leaks or dripping faucets and there is no expansion tank, then you will almost certainly trip the relief valve each time another tankful of water is heated.
 
#5 ·
reply

thanks for the replies, no water leaks now, but I have had 2 for quite a while that I have just fixed in the last month or so. Best I can tell the vibrating pipes seem to happen when the water is first cut on at any location, and sometimes after its cutoff. I can usually make it stop by turning on the water at any location. What is puzzling is I didn't have this problem for the past 6yrs until now, but could the leaks have prevented it? Would an expansion tank fix it, if it is watter hammer, and how common is Water Hammer? I will go to Home Depot and get a pressure gauge. So I just screw it on to a garden hose? Just fyi, I have also replaced all the kitchen, toilets, and sinks exposed lines, the 2 outside spickets, all shut off valves, the garbage disposal, and faucets around 5yrs ago, all the way back to the nipples going into the walls, and I even replaced them(not saying that matters) . Yes, more water comes out of the Pressure relief valve when water is being used like the washer yesterday. When it was filling up, more water came out of the PRV. Is there anyway to fix that without replacing it? Do you have to drain the water heater to replace the PRV? How difficult is the replacement of the prv? and Sorry for the slow reply, I am a single Dad, and my son had a game Tuesday, and a crisis at school yesterday. I hope to have some more time this weekend to try the advice you guys give me, and I really do appreciate it!
 
#6 · (Edited)
When you go to Home Depot to buy a water pressure gauge, I think the best one they sell that comes with a hose bib connector on it might be the Watts brand gauge for about $12. It has a black hand for reading real-time pressure and also a red hand that remembers maximum pressure. The red hand will tell you what the maximum pressure was in your system overnight (or during the day when everyone is at work) when no one used any water.

When folks use a lot of hot water like taking showers or doing the laundry, cold water will enter the water heater. When no one opens any faucet after that, like overnight, the water in the heater will heat up and expand and increase the pressure in your plumbing system. The red had will tell you what that highest pressure was. However, since the PRV on your water heater is leaking, you will not be able to see the maximum pressure that can occur until that leak is fixed.

BTW, I was at our local Home Depot yesterday and discovered that they had an unknown brand water pressure gauge in one aisle and the Watts brand gauge in another aisle. Why they did that doesn't make any sense to me but it could be the same at your Home Depot.

-----

I'm wondering now whether your "leaking" PRV is vibrating the seal and causing the rumbling. Also, what temperature is your water heater set to?

HRG
 
#7 ·
reply to HRG

I will make sure I get the Watts if that is the one you recommend. My water heater was set on the factory setting of 125 up until just a few days ago as one of my attempts to stop the leaking PRV I turned the thermostat on top and bottom of the water heater down about 10 to 20 degrees(there is no temp reading marks below the factory 125 point so it is just a guess. It is just me and my 6 yr old son who live here so we don't use that much hot water anyway. My water heater is an 80 gallon, not the standard 50 Gallon, does that impose any issues? I do have to turn the main water valve off at bedtime, and in the morning before work so my 5 gallon bucket does not overflow. I forgot it yesterday morning, and it was just getting ready to overflow when I got home. Does that PRV thread into the top of the water heater or is it sweated in there? So should I try to get a pressure reading before I try to fix the PRV? Where is a good place in relation to the water heater to install the pressure reader? Thanks again for helping me, Home Repair Guy
 
#12 ·
I will make sure I get the Watts if that is the one you recommend.
The unknown brand water pressure gauge was $9 and the Watts was $12. Watts is a well known brand so I would pay the $3 more and get that one.

My water heater was set on the factory setting of 125 up until just a few days ago as one of my attempts to stop the leaking PRV I turned the thermostat on top and bottom of the water heater down about 10 to 20 degrees(there is no temp reading marks below the factory 125 point so it is just a guess.
The 125 degree setting was fine. Just so it wasn't a higher value.

It is just me and my 6 yr old son who live here so we don't use that much hot water anyway. My water heater is an 80 gallon, not the standard 50 Gallon, does that impose any issues?
Not for any rumbling sounds in the system.

I do have to turn the main water valve off at bedtime, and in the morning before work so my 5 gallon bucket does not overflow.
If a thermal expansion tank is not installed in your system, then turning off the main water valve for extended periods is a really bad thing. It creates a closed system with no where for expanded heated water to go and the increased pressure will cause leaks in your plumbing. It will exacerbate the leaking from the T&P valve on your water heater.

When the main valve (or cold water input valve to the heater) is closed, excess water pressure created when the water heats up (above the city's water pressure) cannot flow back into the city's water line. Water cannot be compressed so it will create leaks in the closed system. Whenever the main water valve is closed, a faucet should be opened to prevent that. Typically, one turns off the main water valve to do work on the plumbing so the system is not closed during the work.

Some cities require a check valve at the water input to the property to prevent back feeding of water. This is similar to closing the main water valve. A thermal expansion tank is essential in that case.

Until you repair your problems, if you close the main water valve, open a faucet in a sink. That will prevent pressure build up in your plumbing system while you are sleeping or at work. Or turn off your water heater but that will mean time to heat the water when you need it.

Does that PRV thread into the top of the water heater or is it sweated in there? So should I try to get a pressure reading before I try to fix the PRV? Where is a good place in relation to the water heater to install the pressure reader?
The T&P (temperature & pressure) valve screws into the water heater.

The water pressure reading should be taken off a hose bib, not at the water heater. The Watts gauge comes with a hose bib connector on it.

Yes do take a pressure reading for information purposes. You can compare it after the T&P valve on the heater is replaced.

Here are some links to instructions and a video on how to replace a T&P valve:

How to replace a PRV on a water heater:
http://www.water-heater-repair-guide.com/waterheaterreliefvalve.html

How to replace a PRV on a water heater:
http://www.cornerhardware.com/index.php?main_page=howto&f=ht065

Video of replacing a PRV:
http://www.youtube.com/watch?v=yUIyc8yqZMg&feature=related

HRG
 
#8 ·
My water heater was set on the factory setting of 125 up until just a few days ago as one of my attempts to stop the leaking PRV I turned the thermostat on top and bottom of the water heater down about 10 to 20 degrees(there is no temp reading marks below the factory 125 point so it is just a guess.
I'd set both thermostats to the same mark; shoot for 120 or an equal tad below 125 if 120 not marked.

My water heater is an 80 gallon, not the standard 50 Gallon, does that impose any issues?
Nope

Does that PRV thread into the top of the water heater or is it sweated in there?
Threaded, usually into the side

So should I try to get a pressure reading before I try to fix the PRV?
The reason for the pressure reading is to see if the leaking is due to high pressure. If the water pressure is high, then the PRV is doing its job by venting the water, relieving the pressure. No sense replacing it if it is ok.

Where is a good place in relation to the water heater to install the pressure reader?
Any hose thread water outlet: outside hose faucet or even the drain valve of the water heater works (I might not choose the water heater drain valve as first choice as then can sometimes not shut off all the way and drip; another problem for another time).
 
#9 ·
reply

my PRV goes into the top center, just wasn't sure if it was threaded when I looked at it. It did look like it was. Do I have to drain the water heater if it turns out I do need to replace the PRV? I did try to make sure both tstats were set to the same temp. I will try to go by home depot today to get the watts wpg so I can get a jump on things for the weekend. Thanks
 
#14 ·
reply

thanks again, that pic is a very good depiction of a water heater. My prv does screw into the top dead center of the water heater. I got the watts water pressure gauge screwed onto my outside spicket like it shows to do on the instructions. How long does it need to be connected to get an accurate reading?
 
#15 ·
reply add on

I have had the meter connected to the outside spicket for about an hour and a half and it is reading 150 psi on the black, and 190psi on the red. Has it been on there long enough, is that a possible reading? Could meter be bad? Does it need to stay on there longer?
 
#16 · (Edited)
I have had the meter connected to the outside spicket for about an hour and a half and it is reading 150 psi on the black, and 190psi on the red. Has it been on there long enough, is that a possible reading? Could meter be bad? Does it need to stay on there longer?
The black needle is a realtime readout. It instantly indicates the current water pressure. 150 psi is much too high for your home's water pressure and 190 psi is out of sight. The excessively high pressure is causing problems in your plumbing system. Normal water pressure for a home should be about 60 psi.
Did you have the main water valve turned off?

Do you have a pressure reducing valve (aka pressure regulator) installed where the cold water line from the city enters your home? Looks like this:


If you didn't have the main water valve turned off creating a closed system, then maybe the city installed an anti-backup check valve which is causing all of your problems. Heated water has no place to expand creating leaks and maybe the rumbling.

1. With the pressure gauge attached, open a different cold water faucet and leave the water running. What's the reading?

2. Then close the water faucet and what's the reading?

When you opened the different cold water faucet in step-1, you released the pressure build up in your system. Closing the faucet in step-2 will give you the real pressure reading for your home since the built up pressure was released. Then at that time, "gently" turn the middle knob on the pressure gauge counter-clockwise to make the red needle just butt against the black needle. Now leave the pressure gauge overnight and see what the maximum water pressure was overnight as indicated by the red needle.

Do you have an expansion tank by your water heater? It will look something like this but maybe a different color:



It is normally connected to the cold water input line to the water heater like this:



The backflow preventer in the picture is what the city would have installed at the input to your property (if your property has a backflow preventer).

You may already know this but just in case not, when hot water expands in the water heater, it affects the water pressure in both hot and cold water lines since the cold water line is connected to the heater's tank. This is why you can read the high pressure at the cold water line hose bib.

HRG
 
#17 ·
reply

There is something in the main line coming in up next to the ceiling in the garage that I have not got a ladder and looked at real close. It doesn't appear to look exactly like what you have there, but I am guessing that it is alot older. My home was built in 1977, were they putting those in the lines at that time? I am at work now, but I was thinking about the pressure I had. The spicket I have it attached to is attached to the main water line before that device that is iline with the cold water. Could that be the problem? Maybe I should move the Watts to the back spicket and check again, what do you think? I did have the main water valve on when I was checking the gauge. How long does it take for the meter to balance out and get an accurate reading? I did what you said when I left this morning and left my sink faucet cracked on, as well as I did last night. I definitely dont have an expansion tank.
 
#18 · (Edited)
There is something in the main line coming in up next to the ceiling in the garage that I have not got a ladder and looked at real close. It doesn't appear to look exactly like what you have there, but I am guessing that it is alot older. My home was built in 1977, were they putting those in the lines at that time?
Set Google to "images" and then google "water pressure reducing valve". The images that display will show you the different types of pressure reducing valves to compare to the thing in your main line. I doubt that that thing is a pressure reducing valve since it's next to the ceiling. They are normally installed for easy access by folks standing on the ground/floor.

I am at work now, but I was thinking about the pressure I had. The spicket I have it attached to is attached to the main water line before that device that is iline with the cold water. Could that be the problem? Maybe I should move the Watts to the back spicket and check again, what do you think?
It wouldn't hurt to check the water pressure at the back spigot. Static water pressure will be the same no matter where it's checked provided there are no leaks in the system and a pressure reducing valve is not between the front and the back. If the pressure is lower at the back spigot, what's the pressure?

I did have the main water valve on when I was checking the gauge. How long does it take for the meter to balance out and get an accurate reading?
As soon as you open any faucet, any built up water pressure will be released instantly. Closing the faucet a few seconds later will insure that pressure readings are the normal pressure.

I did what you said when I left this morning and left my sink faucet cracked on, as well as I did last night. I definitely dont have an expansion tank.
Leaving the faucet cracked on was a good thing if you turned the main water valve off.

I think your primary goals now should be:

1. Ask the city if they installed a back-flow preventer check valve in the water line feeding your property.

2. Determine whether you have a pressure reducing valve installed. If you do, determine whether it's working. If you have one, post and I'll tell you how to tell if it's working.

3. Leave the main water valve open. Install the water pressure gauge on a hose bib. Take a shower or whatever you normally do that uses the most amount of hot water. Set the red needle on the water pressure gauge against the black needle. "Don't open any faucet" for an extended period. See what your maximum water pressure is.

4. You probably should have a thermal expansion tank installed but that's your call. From what you said so far about your pressure readings, I would have one installed if it were my property.

HRG
 
#19 ·
reply

I put the gauge on the back spicket, and turned it on, the red needle did not move off zero. I turned off the water and unattached it, then reattached it. The readings are now about the same as the front spicket. You said something about setting the red needle on the black. I did not manually adjust a starting point for the needles, do I need to do that? There definitely is a pressure reducing valve on my cold water line coming into the water heater. I guess that it needs adjusting or is not working?
 
#20 · (Edited)
I put the gauge on the back spicket, and turned it on, the red needle did not move off zero. I turned off the water and unattached it, then reattached it. The readings are now about the same as the front spicket. You said something about setting the red needle on the black. I did not manually adjust a starting point for the needles, do I need to do that? There definitely is a pressure reducing valve on my cold water line coming into the water heater. I guess that it needs adjusting or is not working?
Roger,

I'm going to start a new thread since that oversized picture that Bob22 posted is making this thread so hard to read in the "preview" mode when I'm responding to your posts. It will have the same subject + part2.

HRG
 
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