At my wit's end. Plumbing issue (Page 1 of 2)
Posted: Yesterday 5:58:44 PM EDT
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About 2 weeks ago, Got a notification from the water company that I was using 5 gallons an hour. Check the house over and notice I am using .01 gallons/ minute. Can't find any leaks. Call plumber. He comes out does the same thing that I did to check and then discovers that my my water pressure was at 120 PSI. Changedout the prv valve and he sets to 70 PSI. Water usage drops to 0 when no one's home. A week goes by no issues. Last week on Wednesday I did one load of laundry. No issues, the second load I start hearing this hammering sound that keeps getting louder. Turn off the washing machine and it goes away. I changed the expansion tank on the water heater, because apparently it wasn't working. Also put on anti-hammer valves on the back of the washing machine. Have flushed the entire house multiple times by turning off the water and opening up all the spigots, then slowly turning the water back on and flush the air out. The washing machine turns on it starts hammering until I shut it off. I also had it happen once or twice with the toilet and an outside spigot that I was running to fill up some containers. Anybody have any idea? 99% of the time it's when the washing machine first starts to fill and it doesn't stop until I shut the washer off, but I have had it happen once or twice with a toilet and outside faucet. Thoughts? |
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I couldn't imagine the prv going bad, but hammer is usually hi psi related. 70 psi is very safe from hammering especially with hammers and an expansion tank in the system. Very weird. Trapped aiir in you lines would only help soften, other than when spitting out air/water/air when flushing. Whats the city water psi doing? Is there any kind of pump in your system? Has your water been dirty? If sediment is going through the main because of a break or flushing it can mess your prv up. |
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Certain washers are known for extreme water hammering, I have it with a Kenmore/LG washing machine. I ended up going with double water hammer arrestors because it would wear out a single arrestor. Not sure if this is your same issue as it only happened once you dropped your pressure. |
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Originally Posted By supernoma: Certain washers are known for extreme water hammering, I have it with a Kenmore/LG washing machine. I ended up going with double water hammer arrestors because it would wear out a single arrestor. Not sure if this is your same issue as it only happened once you dropped your pressure. |
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Originally Posted By Ace-of-Based: You mentioned the hammer sound but didnt mention where its coming from. Is it coming from the washing machine? |
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Originally Posted By boolzi: I couldn't imagine the prv going bad, but hammer is usually hi psi related. 70 psi is very safe from hammering especially with hammers and an expansion tank in the system. Very weird. Trapped aiir in you lines would only help soften, other than when spitting out air/water/air when flushing. Whats the city water psi doing? Is there any kind of pump in your system? Has your water been dirty? If sediment is going through the main because of a break or flushing it can mess your prv up. |
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Originally Posted By skink: About 2 weeks ago, Got a notification from the water company that I was using 5 gallons an hour. Check the house over and notice I am using .01 gallons/ minute. Can't find any leaks. Call plumber. He comes out does the same thing that I did to check and then discovers that my my water pressure was at 120 PSI. Changedout the prv valve and he sets to 70 PSI. Water usage drops to 0 when no one's home. A week goes by no issues. Last week on Wednesday I did one load of laundry. No issues, the second load I start hearing this hammering sound that keeps getting louder. Turn off the washing machine and it goes away. I changed the expansion tank on the water heater, because apparently it wasn't working. Also put on anti-hammer valves on the back of the washing machine. Have flushed the entire house multiple times by turning off the water and opening up all the spigots, then slowly turning the water back on and flush the air out. The washing machine turns on it starts hammering until I shut it off. I also had it happen once or twice with the toilet and an outside spigot that I was running to fill up some containers. Anybody have any idea? 99% of the time it's when the washing machine first starts to fill and it doesn't stop until I shut the washer off, but I have had it happen once or twice with a toilet and outside faucet. Thoughts? What's the pressure from your water main, before the PRV? There are certain flow rates and in/out pressure ranges where PRVs *will* oscillate. If you're north of 100PSI at the mains, that might be part of it. EDIT: I see you mentioned 120PSI, that could be part of it. I don't know a solid solution, I've heard that a dual-stage PRV setup might help, but this is a Q for the pros, not for me. |
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Originally Posted By Jerret_S: Try just partially closing your washing machine supply hose bib. Let less water in as fast is less water to slam when it shuts off and see if it stops? Just a suggestion I bet that would work. |
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I had that when I bought a new washer. Plumber said something to the effect that the valve in the new machines close faster. He installed anti water hammer at the washer and along the lines somewhere. Older house with copper pipes. Still had slight water hammer. Kinda annoying but it is someone else’s problem now. |
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Originally Posted By SpankMonkey: OP try turning the main down or try turning the meter down. God, I hope this works. |
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First, get a psi gauge with hose threads and put it on and verify your current pressure. Remember you lose about 1 psi per foot, so if you check it outside at a hose, your basement might be several psi higher. Went I did this, I had 100psi from the city. Most appliances recommend 40-60psi. I set mine to 60psi. Did you change the pressure on your expansion tanks bladder to match your 70psi setting? |
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| Maybe some debris is stuck somewhere after opening/closing your main water valve. Check and make sure it is fully open as well. I have only seen a couple bad prv’s out of the box after installing hundreds. I’ve seen bad toilet fill valves cause terrible water hammer. Just installing a prv most likely wouldn’t fix your water leaking issue as well. What was running/dripping that was causing the water usage? |
| Don't know if he installed it backwards, but I know that with my two pressure gauges I'm showing 70 PSI which is what he's showing on the receipt, so that's what he set it at. |
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Originally Posted By runawayabc123: First, get a psi gauge with hose threads and put it on and verify your current pressure. Remember you lose about 1 psi per foot, so if you check it outside at a hose, your basement might be several psi higher. Went I did this, I had 100psi from the city. Most appliances recommend 40-60psi. I set mine to 60psi. Did you change the pressure on your expansion tanks bladder to match your 70psi setting? Also, South Central Texas, no basement. |
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I'm not a plumber but 70psi is not high water pressure. If the problem presents itself when the washer starts filling, I'd be looking at the washer. You may have a bad valve in it. I have a water line run to the outside of the house at over 100psi and the only time I get hammer is when a valve is not working the right way. Usually it's partially open or not closing correctly. |
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Originally Posted By skink: Don't know if he installed it backwards, but I know that with my two pressure gauges I'm showing 70 PSI which is what he's showing on the receipt, so that's what he set it at. If it was installed backwards, you would probably have little to no pressure. There are usually arrows on the valve somewhere indicating water flow. Washing machine supply lines should have hammer arrestors on the lines because it is a quick closing valves. Most are built on the valves of the washing machine box, if you have one. If you do not have arrestors on the supply lines, add some |
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Originally Posted By skink: Don't know if he installed it backwards, but I know that with my two pressure gauges I'm showing 70 PSI which is what he's showing on the receipt, so that's what he set it at. If it was installed backwards, you would probably have little to no pressure. There are usually arrows on the valve somewhere indicating water flow. Washing machine supply lines should have hammer arrestors on the lines because it is a quick closing valves. Most are built on the valves of the washing machine box, if you have one. If you do not have arrestors on the supply lines, add some. Maybe the fill valve on your washing machine is bad due to the previous high pressure issue. That could be the source of your leak as well, which you still need to determine I bet. Also, any way you could take a video of it happening? I think most people confuse the sound of water restrictions vs water hammer |
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Probably not the same, but I had a similar issue when I used my shower. Called a plumber and they had no idea what the issue was. Someone suggested I turn off the water to all my toilets and see if it goes away. And it did! I eventually narrowed it down to the one causing the issue and replaced the internal "guts". Problem solved. |
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| Not a plumber, but would running a hose off each wall connection for the washer to a drain and turning them on individually show if it’s a household line issue, cold or hot water issue, or a washer issue? |
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70psi is fine. You're not having a hammer issue if it keeps happening after the solenoid valves on the washer are open. something in the system is vibrating not hammering and it's showing when volume/pressure drops in the system. All the hammer arrestors in the world won't fix it. Could be the pressure reducing valve, a loose washer in a supply stop, busted vacuum breaker on a hose bib, balancing spool in a shower valve, worn ceramic disk in a faucet cartridge etc. Copper pipe can make an insignificant little vibrating washer on one side of the house make it sound like the world's ending on the other side of the house. |
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Originally Posted By FMJshooter: 70psi is fine. You're not having a hammer issue if it keeps happening after the solenoid valves on the washer are open. something in the system is vibrating not hammering and it's showing when volume/pressure drops in the system. All the hammer arrestors in the world won't fix it. Could be the pressure reducing valve, a loose washer in a supply stop, busted vacuum breaker on a hose bib, balancing spool in a shower valve, worn ceramic disk in a faucet cartridge etc. Copper pipe can make an insignificant little vibrating washer on one side of the house make it sound like the world's ending on the other side of the house. This is a great post. Like I said earlier, most homeowners don’t describe water hammer correctly and it is usually a restriction causing the noise. When you have high pressure like you did, it causes stress/failure to everything this post listed. Which is also why I asked what was leaking/running/dripping that that caused the initial call? Was that issue ever properly diagnosed? Installing a prv does not fix a failed shower cartridge, toilet valve, washing machine or dishwasher valve/solenoid. Was your washing machine filling with water when not in use? If you have good working shutoff valves for each fixture, which you probably don’t, try turning them off while the noise is occurring until you get it to stop. That fixture will be your issue. |
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Water leak from the meter to the house underground? It's been so dry here you'd never Notice because the ground soaks it up. Shut everything off on your main before it enters the house. Look at the little triangle spinny thing on the meter. If its spinning or any movement there's a problem. |
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Chat Response: My best guess would be a bad/incorrectly adjusted PRV or a restriction/flow problem immediately downstream of the PRV, rather than trapped air. The big clue is the sequence: * House was at 120 PSI. * PRV was replaced and set to 70 PSI. * Everything was fine for about a week. * Now the hammering occurs while a fixture is actively flowing, especially when the washer begins filling. * It can occasionally happen with a toilet or hose bib. * Replacing the washer’s anti-hammer devices didn’t cure it. That sounds less like classic water hammer and more like a pressure/flow oscillation (“chatter”) somewhere in the supply system. What I’d check first 1. Verify the pressure with a gauge while the washer is filling. This is probably the most revealing test. Put a hose-thread pressure gauge on a laundry connection or hose bib and watch it while the washer is filling. If it goes something like: 70 → 40 → 90 → 30 → 100 → 40… while the hammering is occurring, I’d strongly suspect the PRV (or something immediately around it). A PRV can sometimes oscillate/chatter when there’s a particular flow rate. A washing machine’s solenoid valve opening can put the system right in the range where that happens. 2. Check the PRV’s installation and adjustment. I’d want to know: * What brand/model PRV was installed? * Was it installed in the correct flow direction? * Is there a strainer/screen associated with it, and is it clean? * Is there a bypass/check arrangement? * Is the downstream pressure actually 70 PSI under both static and flowing conditions? The fact that the original pressure was 120 PSI is important. A new PRV is now the main control point for the entire house. Another possibility: the washer’s inlet valve There’s also a very good possibility the washing machine itself is initiating the oscillation. The washer doesn’t simply have a faucet that stays wide open. It uses electrically operated solenoid valves that open and close very quickly. If the washer’s inlet valve is defective, partially restricted, or vibrating, it can create a rapid pressure fluctuation that gets transmitted through the plumbing. The fact that the noise starts specifically when the washer starts filling and continues as long as it’s filling makes me want to test that before tearing into the house plumbing. A simple diagnostic would be: Connect a different appliance/hose to that same supply and see whether you can reproduce the hammering at roughly the same flow rate. Or temporarily run a hose bib at different flow rates. If there’s a particular flow rate where the whole house starts hammering, that’s strong evidence for PRV/pressure-regulator instability rather than the washer itself. I wouldn’t focus much on the air-flushing I don’t think repeatedly flushing the house is likely to solve this. Air in the lines normally doesn’t cause a persistent, repeatable hammering that begins specifically when one fixture starts flowing. And the expansion tank is probably not the culprit either. The expansion tank primarily deals with thermal expansion and closed-system pressure, not a sustained hammering event occurring during washer filling. One thing I’d definitely check, though, is the expansion tank’s precharge. If they installed a new one, it should generally be checked/adjusted with the water pressure removed from the tank side. For a system regulated to 70 PSI, the tank precharge would commonly be set around the system’s cold static pressure (often ~70 PSI), according to the manufacturer’s instructions. My troubleshooting order I’d do this before replacing anything else: 1. Put a pressure gauge on the system. 2. Watch pressure with nothing running. 3. Start the washer and watch the gauge during the hammering. 4. Try a hose bib at various flow rates and watch the gauge. 5. If pressure oscillates dramatically → PRV/system issue. 6. If pressure remains steady around 70 PSI but the washer alone causes it → washer inlet valve/restriction/washer supply hose becomes much more likely. 7. If the same phenomenon occurs at several fixtures at particular flow rates → I’d go back to the PRV and its installation/condition. And there’s one particularly interesting clue I’d ask the poster about: When the plumber installed the new PRV, did he actually measure the pressure with water flowing, or did he just set the static pressure to 70 PSI? Because 70 PSI static does not necessarily mean the PRV is behaving properly dynamically. A PRV that is chattering can look perfectly normal when nothing is flowing. |
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Originally Posted By ropwoo: Probably not the same, but I had a similar issue when I used my shower. Called a plumber and they had no idea what the issue was. Someone suggested I turn off the water to all my toilets and see if it goes away. And it did! I eventually narrowed it down to the one causing the issue and replaced the internal "guts". Problem solved. I'm on an aerobic septic. If my sprinklers come on when not supposed to i usually find a toilet still running. My toilets suck. Happens all the time. |
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Originally Posted By SurfinBrass: 120 psi for residential house water pressure = "Let's try and find the leak we're insisting on making." Shit, I’ve seen 165 at homes before. Most of the municipalities around here all have water psi over 100. Prv’s are a must on homes here. |
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flippflopped Thanks! You've definitely given me something else to consider. What 'm wondering is why if it could be the washer it didn't act up until now, even though the pressure was higher. But like you said it could be the washer, or it could be a defective prv valve that was installed. What other appliance could I attach to the washer hoses to eliminate the washer as a possible source for a hammering? |
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Originally Posted By ropwoo: Probably not the same, but I had a similar issue when I used my shower. Called a plumber and they had no idea what the issue was. Someone suggested I turn off the water to all my toilets and see if it goes away. And it did! I eventually narrowed it down to the one causing the issue and replaced the internal "guts". Problem solved. interesting |
PFG #397
Rob3220:
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Originally Posted By flippflopped: Chat Response: My best guess would be a bad/incorrectly adjusted PRV or a restriction/flow problem immediately downstream of the PRV, rather than trapped air. The big clue is the sequence: * House was at 120 PSI. * PRV was replaced and set to 70 PSI. * Everything was fine for about a week. * Now the hammering occurs while a fixture is actively flowing, especially when the washer begins filling. * It can occasionally happen with a toilet or hose bib. * Replacing the washer’s anti-hammer devices didn’t cure it. That sounds less like classic water hammer and more like a pressure/flow oscillation (“chatter”) somewhere in the supply system. What I’d check first 1. Verify the pressure with a gauge while the washer is filling. This is probably the most revealing test. Put a hose-thread pressure gauge on a laundry connection or hose bib and watch it while the washer is filling. If it goes something like: 70 → 40 → 90 → 30 → 100 → 40… while the hammering is occurring, I’d strongly suspect the PRV (or something immediately around it). A PRV can sometimes oscillate/chatter when there’s a particular flow rate. A washing machine’s solenoid valve opening can put the system right in the range where that happens. 2. Check the PRV’s installation and adjustment. I’d want to know: * What brand/model PRV was installed? * Was it installed in the correct flow direction? * Is there a strainer/screen associated with it, and is it clean? * Is there a bypass/check arrangement? * Is the downstream pressure actually 70 PSI under both static and flowing conditions? The fact that the original pressure was 120 PSI is important. A new PRV is now the main control point for the entire house. Another possibility: the washer’s inlet valve There’s also a very good possibility the washing machine itself is initiating the oscillation. The washer doesn’t simply have a faucet that stays wide open. It uses electrically operated solenoid valves that open and close very quickly. If the washer’s inlet valve is defective, partially restricted, or vibrating, it can create a rapid pressure fluctuation that gets transmitted through the plumbing. The fact that the noise starts specifically when the washer starts filling and continues as long as it’s filling makes me want to test that before tearing into the house plumbing. A simple diagnostic would be: Connect a different appliance/hose to that same supply and see whether you can reproduce the hammering at roughly the same flow rate. Or temporarily run a hose bib at different flow rates. If there’s a particular flow rate where the whole house starts hammering, that’s strong evidence for PRV/pressure-regulator instability rather than the washer itself. I wouldn’t focus much on the air-flushing I don’t think repeatedly flushing the house is likely to solve this. Air in the lines normally doesn’t cause a persistent, repeatable hammering that begins specifically when one fixture starts flowing. And the expansion tank is probably not the culprit either. The expansion tank primarily deals with thermal expansion and closed-system pressure, not a sustained hammering event occurring during washer filling. One thing I’d definitely check, though, is the expansion tank’s precharge. If they installed a new one, it should generally be checked/adjusted with the water pressure removed from the tank side. For a system regulated to 70 PSI, the tank precharge would commonly be set around the system’s cold static pressure (often ~70 PSI), according to the manufacturer’s instructions. My troubleshooting order I’d do this before replacing anything else: 1. Put a pressure gauge on the system. 2. Watch pressure with nothing running. 3. Start the washer and watch the gauge during the hammering. 4. Try a hose bib at various flow rates and watch the gauge. 5. If pressure oscillates dramatically → PRV/system issue. 6. If pressure remains steady around 70 PSI but the washer alone causes it → washer inlet valve/restriction/washer supply hose becomes much more likely. 7. If the same phenomenon occurs at several fixtures at particular flow rates → I’d go back to the PRV and its installation/condition. And there’s one particularly interesting clue I’d ask the poster about: When the plumber installed the new PRV, did he actually measure the pressure with water flowing, or did he just set the static pressure to 70 PSI? Because 70 PSI static does not necessarily mean the PRV is behaving properly dynamically. A PRV that is chattering can look perfectly normal when nothing is flowing. I love AI when its used like this |
PFG #397
Rob3220:
"Walmart Ammo isn't good for anything. I don't think it even breaks skin. Rounds are made of compressed Jell-O, if I recall correctly."
Rob3220:
"Walmart Ammo isn't good for anything. I don't think it even breaks skin. Rounds are made of compressed Jell-O, if I recall correctly."
| Do you have a good crawlspace to get down where the pipes are? I do and I went down there while my wife turned the shower/bath on and off and found where our copper pipes were running along a floor joist. Zip ties and “bam” no more hammer. |
OK, see you later, Redcoat…
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I was having to replace valves in all the toilets every 13 or so months for a few years. Then the water heater sprung a leak. Flooding with the washing machine (which the builder plumbed upstairs). Turns out, the pressure regulator had a failed o-ring. Had 120 psi inside of the house. Learned that when I stopped being dumb, and got a gauge at Home Depot. I keep it plugged into the hot water heater drain valve. Very useful. |
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With a 50psi pressure drop across that single PRV, you may need to go to two PRV’s in series. Can you post a pic of the PRV that was installed? Let’s look at the specs on that valve. |
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I, too went through your process of elimination. A good plumber educated me while installing a new PRV. I learned that the (NEW! OR used) PRV can fail in these ways: Fully open or closed, or partially. My PRV was not really that old (several years), yet failed almost fully shut. My 2 cents, John |
| I am going to check it when I get home. I am going to call the plumber and see if I can reduce the pressure to 55 psi and see if that helps. If not, they are going to have to come back out. |
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Originally Posted By skink: I am going to check it when I get home. I am going to call the plumber and see if I can reduce the pressure to 55 psi and see if that helps. If not, they are going to have to come back out. There is nothing wrong with keeping the pressure where it is. 55 is too low IMO. |