loud howling noise coming from pressure regulator
- Thread starter rayjoe123
- Start date
Users who are viewing this thread
Redwood
Master Plumber
I personally think that in the course of the PRV doing its job there is going to be some resonance induced. The frequency will vary with the flow rate but it is there. If the length of the unsupported pipe is at the tuned length for that frequency the pipes will sing! The hangers now have the pipe length off tune and there is no noise.
Sponsor
Paid Advertisement
Yes, a resonance effect. Maybe the prv manufacturer is gambling on very few people having unsupported pipe lengths that are just right to cause this.
I imagine a few feet of water-filled pipe has a pretty low resonant freq.
If it's 396 Hz it's supposed to. . .well, you can read the title
http://www.youtube.com/watch?v=gm7ZL-PrYd8
Last edited:
liplumber
New Member
Yea plumbing issues like this can be tedious. It's always tough to swallow when a plumber fixes or replaces something expensive, and the plumbing problem isn't resolved. I would check the expansion tank as well. That is good advice to just go ahead and buy yourself a cheap gauge just to see. My friend runs a cesspool service suffolk county and he recently had a plumbing issue similar to this on a residential job. The problem turned out to be not what he originally thought at all. Sometimes you just got to test test test. Darn plumbing.
rayjoe123
New Member
well guess what the noise is back. it doesnt matter what valve i turn on, shower, faucet i can hear that howling noise at the prv. i called out another plumber and he checked the water pressure after the prv and it read 50psi he said the prv is good in his opinion, but he does not know where or why the noise is there, lol. i dont know what to do now. i dont want to call another plumber and him tell me the same thing......i dont have an expansion tank on my water heater and never did . i lived here for 15 years and never had one. but this sound just started a few months ago. the water heater is brand new ( bradford white, electric ) two new prv valves............the water heater and 1st prv were installed the same day. but i had the noise issue before i installed the new water heater the only reason i had a new water heater put in was because old one was 15 years old and just wanted to change it out..........
Last edited:
Find as many ways as you can to change the pitch or stop the noise or make the noise worse.
Open one or more taps to change the water pressure, clamp the valve to the wall, clamp the valve in such a way as to put a slight torque on it, clamp other pipes using rubber bushings, throttle down the flow at the water meter valve, isolate copper pipe sections using plastic pipe, etc..
Fixes you try that don't touch the symptom tell almost as much as those that do.
How do you know the noise originates in your house? Maybe the PRV just amplifies an existing vibration from outside your house and is not the root cause.
I guess I'm looking for a hopefully narrow PSI/GPM region where you always get the noise and other PSI/GPM points where the noise never shows up.
Last edited:
rayjoe123
New Member
what if i eliminate the pressure reducer and have a plumber solder in straight copper pipe and then see if i still hear the noise. this way i will be able to tell if it was the prv or something else. if the noise stops after i take the prv off line then i would say that maybe i have the worst luck and got a couple of bad prvs. but if the noise is still there after i take the prv off line then it would be a different problem and i can take my focus off the prv. the reason im leaning towards the prv is because i turn on a faucet and you can hear the loud noise right at the prv. it makes the noise even if i dont turn on a hot water valve, i can turn on a cold water valve only and i hear the noise. so, i think i will call in a plumber and have him take the prv off line so i can test it, and then maybe i can eliminate the prv.......... Thanks. for all the help from everyone this is a very good forum , im glad i found this on the net........ have a good holiday to everyone.......... thanks again...... i will keep you all posted on the results of this noise problem........
rayjoe123
New Member
i called in a different plumber today. and all he did was he adjusted the PRV. the PRV was factory set at 50 psi, he turned on the shower upstairs and then went downstairs to basement and the noise was really loud he adjusted the nut/screw ontop of the PRV to apply more psi until the noist completely stopped. he then checked with a guage to see what the pressure was and it was around 68psi. he said thats perfectly fine. i went and turned on different faucets to make sure there was no more noise and there was no noise it was gone. he said that maybe the incoming pressure was to high and it was going through the PRV and reducing down to 50psi was a big increase causing the pipes to whisle, if he touched any part of the 3/4" pipe after the PRV the noise was gone and thats when he started turning the screw on the PRV until the noise completely was gone. do you think the problem is gone does that make any sense or do you think he just fixed it temporarly and im going to have the noise from hell back. right now im out of the dog house with wife, but if noise comes back, im back in dog house.......... i just dont understand why the noise would stop when he increased the PRV water pressure. the PRV i have can only be adjust to 75 psi max. he said normally as long as its not over 80 psi i should be ok. that just sound really crazy that all this time all that needed to be done was a simple screw adjustment to make the noise go away... any intakes on this.
Jadnashua
Retired Defense Industry Engineer xxx
First, what is the incoming water pressure. If it is extremely high, in some rare circumstances, you may need TWO PRV's in series, each dropping the pressure within their maximum ranges. Second, GET AN EXPANSION TANK!
Even if the PRV has a bypass, when you use a lot of hot water, that NEW gas WH (when the problem started) heats up that cold water, it expands. This WILL raise the pressure at least to the incoming pressure (if it has an internal bypass in the PRV), and that backflow could be part of the problem. When the WH is running, the weakest point in the system will exhibit problems first. This is often a toilet fill valve (which can create its own noises), but it could be anywhere in the system. Have you ever noticed any discharge from the WH T&P valve? ANY closed system NEEDS an expansion tank. If the new WH has a faster recovery than the old one, the pressure can rise quicker. Does the noise relate to (after) the use of hot water at all? IF so, then the expansion tank (which you should have regardless) will stop it.
Even if the PRV has a bypass, when you use a lot of hot water, that NEW gas WH (when the problem started) heats up that cold water, it expands. This WILL raise the pressure at least to the incoming pressure (if it has an internal bypass in the PRV), and that backflow could be part of the problem. When the WH is running, the weakest point in the system will exhibit problems first. This is often a toilet fill valve (which can create its own noises), but it could be anywhere in the system. Have you ever noticed any discharge from the WH T&P valve? ANY closed system NEEDS an expansion tank. If the new WH has a faster recovery than the old one, the pressure can rise quicker. Does the noise relate to (after) the use of hot water at all? IF so, then the expansion tank (which you should have regardless) will stop it.
rayjoe123
New Member
no discharges from t&p valve, i have lived here for almost 15 years and never had an expansion tank. this problem just started a few months ago. i have an electric 40 gal water heater. the incoming pressure was almost 100 psi before the PRV. I already had the PRV replaced three times because the other 3 plumbers thought i was just having bad luck and getting bad PRVs. the noise is there even when you turn on cold only. if i turned on the cold water utility tub faucet the loud noise was coming from PRV valve, it didnt matter what cold water faucet in home i turned on the noise was there. they installed the watts 558 model PRV valve. even when the water heater was off line meaning the breaker turned off and shut off valve on cold side of water heater turned off, you still here the noise if you turn on any faucet cold or hot. and the noise was very loud (whisling). this last plumber basically turned the PRV screw to let more psi through it and the noise completely stopped. we put water heater back on line and went to all faucets and checked them all individually cold and hot seperately and then cold and hot at same time, no noise. we even turned on the shower to make sure and the washing machine no noise. the water heater is brand new (bradfordwhite) but in my area hardly anyone has expansion tanks. I install carpet and i have only seen a few expansion tank that are installed on water heaters.......... im not saying that its not a bad idea to have one,I would liket to put one on my water heater but right now i spent to much money on plumbers and did not want to spend more for them to install an expansion tank, unless i can do it myself . but i dont see how an expansion tank can be the problem if we took the water heater out of the picture and turned on only cold water facuet and the noise was still there. but as of right now i have no noise after he adjusted the screw on top of the PRV he turned it up about 20 psi higher and the noise quite..... the psi was at 50 now its at 68 psi about 20 psi higher.and i have no noise. im hoping this fixes the problem and does not just cover it up for now and the noise starts again. im tired of paying all these plumbers , and no results. lol.
Last edited:
Jadnashua
Retired Defense Industry Engineer xxx
A closed system requires an expansion tank. If the T&P isn't discharging, then something else is leaking to relieve the pressure. Water isn't compressible, when it is heated, it expands, it has to go somewhere. The fact you've had a PRV for a long time and no expansion tank just means that something in your house is leaking (or getting stressed by expanding - maybe the washing machine hoses - wait until that stress causes it to burst!) to relieve that pressure (most likely a toilet, but any faucet that drips could do it). Without a PRV or other checkvalve, when the WH is heating without water flow, it pushes back that expanded water through to the supply.
One possibility is that with high GPM a high input/output pressure differential implies that the PRV has to absorb more power, since the power of moving water is proportional to GPM x PSI.
He reduced the differential and so reduced the energy that the PRV had to absorb.
Just to confirm, can you post specs to your PRV? I'm looking for max differential pressure vs. GPM. I'm guessing the product of the two should be a constant, depending on the design of the PRV.
If this is so, then I guess if the city increases their pressure your noise might return. And, at the old pressure setting there should have been some low value of GPM that gave no noise.
This spec. request should have been my first question.
Last edited:
rayjoe123
New Member
One possibility is that with high GPM a high input/output pressure differential implies that the PRV has to absorb more power, since the power of moving water is proportional to GPM x PSI.
He reduced the differential and so reduced the energy that the PRV had to absorb.
Just to confirm, can you post specs to your PRV? I'm looking for max differential pressure vs. GPM. I'm guessing the product of the two should be a constant, depending on the design of the PRV.
If this is so, then I guess if the city increases their pressure your noise might return. And, at the old pressure setting there should have been some low value of GPM that gave no noise.
This spec. request should have been my first question.
OK. i will check...... should i have a plumber install an expansion tank. or can this be done by myself. now im worried about something explodeing in my house due to what jadnashua stated. i had never had an expansion tank on any of the homes i lived in, In my area. this house has been tested for leaks and there are no leaks , i have no toilets leaking or faucets dripping and my T&P valve on water heater is not leaking or dripping. If i need to have one put on , i will do it if its going to be a safety issue. i surely do not want my water heater or pipes to explode because i dont have an expansion tank..............
Jadnashua
Retired Defense Industry Engineer xxx
Things won't explode! But, if the PRV IS working properly, the internal house pressure can rise quite high after a lot of hot water use as it gets reheated...it must expand - that's just a law of nature! Now, without a PRV or a checkvalve in the house (called an open system), that water volume just pushes back into the supply. A PRV closes off that path (and becomes a closed system - or maybe better called a one-way system). Some PRV's have an internal bypass. If the one you have, when the house pressure rises to match the incoming supply pressure, it will allow water back, so while it will rise, it will peak at the supply pressure. Now, the actual volume of that expanded water depends on how cold it was coming in (denser) and how hot your WH is set (less dense - ie., expanded) and the capacity of the WH tank. It generally isn't that much, but any just raises the pressure - expands the supply hoses to things, and stresses everything. But, the longer the stress, the more likely something will give way. the more common things are washing machine hoses; leaking toilet fill valves, or a leaky faucet.
Get a water pressure gauge. Screw it on where it will fit (it often comes with a hose type connector, but you can use adapters to put in anywhere). Get one that has a tattle-tale hand (max reading). Leave it attached overnight and after you've done your largest hot water use (often in the morning). Look at the static and max pressure. Without an expansion tank on a closed system, if everything is working properly, the pressure WILL rise after the WH reheats water. The more hot water used, the larger the volume increase. If it doesn't rise, at least to the incoming water pressure, something isn't working properly. An expansion tank is cheap protection for all of the plumbing in the house.
They aren't all that hard to install. Cut the cold water supply after the shutoff to the WH, put in a T, solder a threaded coupling on the leg of the T, screw in the tank, support it properly, and you're done. Well, you should first adjust the precharge of the tank. It has a valve just like a tire. Generally they come with about 40psi from the factory, but it is best to adjust it to the static water pressure out of the prv. You need to do this before you connect it to the water supply, otherwise, you'll just read the water pressure, regardless of the air pressure in the thing (unless you set the air pressure higher than the incoming water pressure).
Get a water pressure gauge. Screw it on where it will fit (it often comes with a hose type connector, but you can use adapters to put in anywhere). Get one that has a tattle-tale hand (max reading). Leave it attached overnight and after you've done your largest hot water use (often in the morning). Look at the static and max pressure. Without an expansion tank on a closed system, if everything is working properly, the pressure WILL rise after the WH reheats water. The more hot water used, the larger the volume increase. If it doesn't rise, at least to the incoming water pressure, something isn't working properly. An expansion tank is cheap protection for all of the plumbing in the house.
They aren't all that hard to install. Cut the cold water supply after the shutoff to the WH, put in a T, solder a threaded coupling on the leg of the T, screw in the tank, support it properly, and you're done. Well, you should first adjust the precharge of the tank. It has a valve just like a tire. Generally they come with about 40psi from the factory, but it is best to adjust it to the static water pressure out of the prv. You need to do this before you connect it to the water supply, otherwise, you'll just read the water pressure, regardless of the air pressure in the thing (unless you set the air pressure higher than the incoming water pressure).
rayjoe123
New Member
OK. sounds good. i will check it and maybe try to tackle installing one myself. i hear watts makes a good thermal expansion tank.. thanks again.
rayjoe123
New Member
Ok , I am city. but i will take your advice and go ahead and add one. Thanks again for everyones help. have a good holiday to you all.....................
Similar threads
