Rattling noise behind refrigerator,.......water line.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Marc46, Jul 27, 2008.

  1. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    My mother who lives about 20 miles from me has been complaining of a noise behind her fridge for several days now.

    It is a GE Profile SS side by side, about 3 years old.
    I went over there yesterday, and identified it as the icemaker line which is copper, and coiled behind the fridge.
    I know it is normal to get movement when the icemaker fills or the door water dispense is being used.

    I turned off the icemaker, and also verified there was no air in the lines.
    What happnes is about every three to ten seconds the coil will rattle as if pressure is passing through the tube, even though no water is being used anywhere in the house. It will last from a few seconds to close to twenty seconds before being repeated.

    I am truly confused by this, since I am usually able to fix about anything. I have run my own HVAC business for 17 years.

    It almost appears like there is a water pressure "pulsation" taking place within her plumbing lines.
    I did notice if I opened a faucet or two in different areas of the house, the rattling would quit, or become almost unable to be heard.
    That fact also tells me it is not being caused by a vibration from the running fridge,........plus the fact that this happens even when the fridge is off in a defrost mode.

    Anybody have any suggestions, or ideas to pursue.
    I put it here because I am certain it is plumbing related.

    Thanks from a new member!
  2. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Polterguists???:eek:

    Seriously, It could be a number of things.

    Have you checked to see if it happens with the stop valve turned off?

    You may want to start by taking a pressure measurement with a gauge that screws onto a hose bibb and look for fluctuations in pressure.

    Does she have one of these on the water supply coming into the house? They are usually just after the meter.

    [​IMG]
  3. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Redwood,
    I intend to pull the fridge within the next day or so. I presume it will stop when I turn off the feed line to the fridge.

    I have thought of replumbing the icemaker in plastic tubing, but wish to find out what is causing this apparent "surge".

    She is on city water, and I do NOT believe that she has a pressure regulator after the meter, but I will check.

    I also am going to get a bib mounted gauge to watch for fluctuations.
    Some history,............a while back she was experiencing low water pressure to her sprinkler system. Turned out to be the number of homes being put on the current system, and I believe the ran her a 1" main and meter.

    Since then the plant has been upgraded, and has been fine until about three or four days ago.
    She thinks it might be due to that 1" main,.......but I can't see it, as her inside plumbing, nor the feed to the house has been changed sizewise. Also the new plant went on line almost a year ago.

    Thanks much for the advice,........this is making me nuts, and you know the help you get from the local utilities!:eek:
  4. Terry

    Terry Administrator Staff Member

    Messages:
    15,121
    Location:
    Bothell, Washington
    It sounds like a bad PRV to me too.

    Or you can check to see if a toilet is leaking in a bathroom too.
  5. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Thanks guys,........I will check for a PRV.
    She may have one, I just do not remember seeing one in her meter box.

    She has one of the wonderful RF meters that are read from the vehicle.
    Stopping to get a bib gauge this evening.

    Terry,.........as far as I know there are no toilets leaking.
    Reason I know this is a few months ago her water bill was unusually high.
    I checked the obvious, and also watched her "electronic" meter for any flow with nothing running in the house. Sat there for about 5 minutes, and saw no flow.

    Maybe the suggestion of Poltergeists might be true!:D

    Edit: Terry thanks for the nice forum!
    I intend to help, as well as ask here,........most of my help will be on the HVAC side.
    Nice site!
    Last edited: Jul 27, 2008
  6. Gary Swart

    Gary Swart In the Trades

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    Location:
    Yakima WA
    Typically a PRV is located inside the house right after the supply line comes in. I would not downgrade to plastic tubing, copper is still the best you can use. If the line comes off of the supply line with a saddle valve, that is what I would change to a ball valve with necessary adapters and fittings to go to the copper. I'm not suggesting this is the problem with the noise, just a good idea.
  7. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Gary,........if the PRV is not at the meter, then there is not one.
    We are in Florida.
    All the plumbing is roughed in before the slab pour,.......typically monolithic.

    The house inlet is underground from the utility point, and there are no access "hatches" per se.

    I am on a well myself, but she is on city utilities.
    I prefer my well.:)
    No water bill, and I run my own "treatment" facility here. Comes out of the ground through a large sediment filter, and then is injected by a chlorine pump.
    Goes to a settlement tank, and then through a carbon filter to remove the chlorine, and then to a softener, before entering the house.

    I have also installed a RO system at my kitchen sink location, and plumbed my icemaker supply from the RO outlet.

    I love the water I have here!

    I will figure this out with the help from here,.......thanks guys!
  8. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Update

    OK guys,.....here is the rest of the story.
    Last night I picked up a bib gauge and went over to her place.
    I installed the gauge, and proceeded to watch the pressures.

    It was sitting around 72psi,........but a severe "flutter" in the gauge with NOTHING in the house being used. I would estimate a range of around 8 to 12 psi, and it was a very rapid needle fluctuation.

    Went inside, the noise is happening behind the fridge at about the same frequency of the gauge.
    Pulled the fridge to find out that there is a "feedbox" in the wall, with a 1/4 turn shutoff, with a small anti-hammer riser mounted next to it. I figured the line was copper previously due to the noise, but I was wrong. It was a 1/4" grey plastic tube.
    I watched the tubing literally "jumping" around in intervals,..........almost like someone was on the other side of the wall "whipping" the other end of the tubing.
    I turned off the valve, and of course it immediately stopped.

    I stayed over there last night, and went out to check the gauge at 6:30AM.
    Reading a steady 70 to 75psi, with no "oscillation". Again,.......nothing being used in the home.
    I witnessed something I found very strange in a few minutes. The pressure slowly dropped to about 40psi, and then suddenly climbed smooothly to almost 95psi, before returning to the 70 range.
    I pulled the fridge out again, and turned the water to the fridge back on, and watched the tubing,............no movement at all.
    Pushed the fridge back, and checked the gauge again before I left. Still steady in the 70 range.
    I told her to tell me when it starts jumping around again, as I am going to try and stop by after work.
    I expect to see the "fluttering" in the gauge again.

    I looked for a PRV, but could find none. As I said before, all that appears to be in her meter box is one of those RF electronic meters with the little antenna "bud", and the half flip up cover that reveals the display. I dug around after the meter, and found nothing on the downstream side of the meter. I have no idea if a PRV is possibly built into these style meters?

    Long story short,...........to me, a certain "non-expert", it appears to be from the utility side, and nothing in the house. Last night when I first put the gauge on, it was like watching pressure "fluctuations", coming directly off of a large pump or something. The needle was literally "shaking" in that range I gave above.

    Hopefully this will enable someone to either dispute, or confirm what I am thinking at this point. Any help would be appreciated, as I will have a nightmare I am sure, trying to get the utility company to catch this, and then remedy it!
    Thanks Again.
  9. Redwood

    Redwood Master Plumber

    Messages:
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    Location:
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    It certainly sound like you are getting the funny pressure fluctuations from outside and the water supplier may have a problem they need to track down. The pressure spike to 95 Psi. is a concern. Did the gauge you picked up have a lazy hand that will indicate the maximum pressure reached? I would let it record over a 24 hour period to see what the highest pressure is. Frequently pressures go higher at night while they top off storage tanks.

    A Pressure Reducing Valve (PRV} is needed if the pressure goes above 80 Psi. which you indicate has happened. A Thermal Expansion Tank should also be installed on the water heater inlet. A PRV without a bypass would act as a check valve and eliminate the fluctuations as well. The pressure spikes would go to the set point of the PRV and no higher. Once it reached that pressure there would be no added pressure changes to the fluctuations would be cut off.
  10. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Redwood,......thanks for the input.
    Unfortunately all I was able to get was a 10 buck cheapo with no "high" hand.
    I was shocked to see the pressure drop to 40, and then slowly rise that high before returning to the 70 range.
    She has a NG water heater, but no expansion tank.
    If I can get no action from the utility company,.........can a PRV like you mention be mounted in a box in the ground?

    All she has is a run to the house inlet which is 3/4" pvc I believe, and of course is underground. No crawlspace,......monolithic slab construction.

    I like the idea of that, as I could set the max pressure at say 65 to 68 psi, and that would eliminate all of the fluctuations I have seen so far,.......plus protect against any major surges.
    I am concerned after seeing that as she has that CPVC plumbing since the house is only about 4 years old. I guess there are pros, and cons between that stuff, and copper, on both sides.

    Is that something that the utility company should have to put in, or would myself, or more likely a plumber have to do it?
    Thanks again.
  11. Redwood

    Redwood Master Plumber

    Messages:
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    Location:
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    Here we don't have meter boxes but yes that is where it would go.
    We install them in underground storage rooms under houses!:D

    As for the install typically the customer has resposibility and whether you choose a plumber or, DIY, that is up to you and your abilities.
    Hopefully you know your limitations and can make the right choice.
  12. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Yes I do!:D
    Actually I am quite certain I could do this, but being the time of the year it is, and the trade I am in,........I will most likely pass this off to a professional plumber!
    That way, I can't be griped at if something happens, which is another major "plus."
    Heck,.......I'll even pay for it, since it's my "momma".

    Is Watts still the best for this stuff?
    I used to use a lot of their stuff on commercial boilers.

    Thanks again though for reading my "saga", and giving good advice!
  13. Redwood

    Redwood Master Plumber

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    Location:
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    Watts is good.
  14. Gary Swart

    Gary Swart In the Trades

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    Location:
    Yakima WA
    Recently someone wrote about newer PRVs that allow thermal expansion to get past them and thereby eliminate the need for an expansion tank. I would make sure which type of PRV you get, new style or old style and know for certain whether an expansion tank is needed or not.
  15. Redwood

    Redwood Master Plumber

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    That is specifically why I told him not to get one with the bypass. He wants it to remain at the highest pressure and not bleed back down to keep the pressure pulsations in check. Therefore the expansion tank is needed.
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Location:
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    The automatic bypass may not help much depending on the supply pressure...it will only bypass if the internal pressure exceeds the incoming pressure, and if you have excessively high incoming pressure, the T&P may trip first. In this specific situation, it probably would work since the supply is not excessively high. Still, a tank will keep peak pressure in check.
  17. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    Now you guys are really getting me confused!:D

    The water inlet to the house is on the north side, which is where I figured the PRV would be installed in an underground box right before it enters the home.

    The gas water heater is on the opposite side of the house.
    I assumed if I put in the PRV, and set it for say 65 psi, that there was no longer any need for mods to the water heater.
    What am I missing here?

    Geez,.......I can see I am going to have to call a plumber!:D
  18. Redwood

    Redwood Master Plumber

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    Location:
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    Relax... All is well!

    With PRV's some of them have a section that allows excess pressure to go backwards to the city side of the water supply. You do not want this feature on the valve you use. You want what ever pressure allowed through the PRV to stay on the house side. This will lock out those pulsations once the pressure gets to the set point of the PRV. THe pressure will be allowed to go higher up to the set point but never lower until water is used.

    With this you will want a Thermal expansion tank installed on the water inlet of the water heater. As it would be a closed system and subject to thermal expansion.
  19. Marc46

    Marc46 HVAC Contractor

    Messages:
    102
    Location:
    Central Florida
    I think I have it!
    The PRV is setting the max pressure allowed into the house lines, and at the same time would not allow any higher pressure to move in reverse to the city side,..........it would be kind of "locked into the house plumbing?

    If there was a rise in pressure in the hot water tank,.........it would not be able to disperse back through the PRV, and only the pressure relief on the heater itself, would take care of it, which is too high for the pipes inside the house to handle safely.

    Am I on the right track,..........or a moron?
    Feel free to tell the truth!:D
  20. Terry

    Terry Administrator Staff Member

    Messages:
    15,121
    Location:
    Bothell, Washington
    Yes
    Yes,
    I mean yes. The PRV creates a "closed" system, and that is why you add the expansion tank.

    You should also have hammer arrestors on the icemaker, dishwasher and clothes washer.
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