Seesawing Water Meter Flow Detector


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Old 01-14-19, 04:37 AM
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Seesawing Water Meter Flow Detector

Yesterday I came home to a flooded meter box. The pipe about 6 inches into the service side broke right at the connector to the meter. This was fixed but as we were watching the meter, the flow detector was seesawing.

The utility company said this was likely just pressure in the house stabilizing and would check in the morning(today). Meantime I was able to track this down to possibly the water heater. I shut off each valve in the house one by one and when none of them fixed it, I tried the shutoff to the input side of the water heater and that finally did it.

This seems odd because I've looked at the flow detector before on the meter and it did not used to do this.

It seems to have little net forward motion but does have some. I turned off everything in the house and left for 2 hours, checking the meter reading before. The usage needle moved half of a tenth of a gallon in those roughly 2 hours.

My question is could this be thermal expansion and contraction? Would it be happening that fast? The back and forth seems to happen every 3-10 seconds in slightly random intervals and the forward and backwards are not in a 1:1 ratio. Sometimes it turns backwards 3/4 and then forward 1/8 for example.

I did see when the neighbor turned on something in their house (both our meters are in the same box) and saw similar back and forth on mine although it was more constant and 1:1 motion of a seesaw (quarter turn forward for 1 second, quarter turn back for 1 second, stop for 1 second, repeat).

My fear is I have a pinhole leak in the pipes downstream of the water heater somewhere but not sure it would cause it to go backwards as well as forward.

I would have thought it was just the meter after seeing the neighbor's water usage causing this except for the fact that turning supply off to water heater causes it to go away.

Sorry for the long post but any ideas/suggestions/input would be appreciated. Thanks!
 
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Old 01-14-19, 05:23 AM
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I have seen the flow indicator on older mechanical meters show a back and forth surging so I would say it's normal. I think it is water pressure fluctuations in the system. When the pressure rises more water is forced into the home. Then when the pressure decreases water flows out. This can be more apparent if you have an expansion tank on your water heater as the cushy air is easy to compress.

The flow you saw after two hours is only about 6 ounces so it's possible the water pressure changes could be responsible. I would repeat the test over a longer period of time to insure that you don't have a tiny leak.
 
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Old 01-14-19, 05:33 AM
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Thanks! No expansion tank unless one is built into the water heater but I do have air chambers that were recently recharged. Would air chambers do the same thing? Its possible they may have been water logged when I noticed this steady over a year ago.

Would 4 hours be sufficient for a test? I just want to get the duration correct. What would be a good tolerance for the test? Something like less than 12 oz for 4 hours?
 
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Old 01-14-19, 08:50 AM
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Utility Company came out and I showed him the meter movement (flow detector and half of a tenth of a gallon) and he agreed it should have stabilized by now and should have 0 movement so it would be a good idea to have a plumber check it out.

A thought I had was to ask the plumber to put a shutoff at the hot side of the water heater to at least eliminate the water heater or point to it. The thinking is that its either thermal expansion or a pinhole leak. Will update with my findings as I've seen this question happen before.
 
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Old 01-14-19, 08:58 AM
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The longer your test the more accurate it will be. Leave everything on in your house but not using water and see if your meter moves over night or while you are at work.
 
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Old 01-14-19, 09:14 AM
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Originally Posted by Pilot Dane
The longer your test the more accurate it will be. Leave everything on in your house but not using water and see if your meter moves over night or while you are at work.
Sounds good. I also had a thought that it might be the T&P valve on the heater (as that's really the only thing I can remotely test at the moment) so I gave it a brief test. May be wishful thinking but it seems to be better and I've only seen the leak detector go backwards since that, presumably thermal expansion as it allows that small amount of water get up to temp.
 
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Old 01-14-19, 10:23 AM
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For what it's worth, I often see the flow spinner bob back and forth. It has to do with pressure in the rest of the system as people use water. If you were to put a pressure gauge on the line, you'd see minor fluctuations all the time, though too minor to notice in any normal usage (unless your at the top of the hill or something, that's when it starts making a difference).
 
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Old 01-14-19, 11:17 AM
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Originally Posted by Zorfdt
For what it's worth, I often see the flow spinner bob back and forth. It has to do with pressure in the rest of the system as people use water. If you were to put a pressure gauge on the line, you'd see minor fluctuations all the time, though too minor to notice in any normal usage (unless your at the top of the hill or something, that's when it starts making a difference).
I would tend to agree with this but my neighbor's meter is right next to mine and not having this issue. I'm in Texas in the part where its flat enough to see very far away :-)

If it weren't for the fact that 1) when I cut off the hot water heater it stops 2) my neighbors don't have this problem and 3) it did not used to do this, I'd agree though but definitely appreciate the input.

I think I may have found a small leak in the wall though. Every 45-48 seconds I hear something that sounds like a water drop and hit something. I have one of those pinhole cameras for my phone that. If I have time, I'm going to make some pinholes and see if I can track down the drops. I checked the attic above and everything was dry there.
 
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Old 01-14-19, 11:43 AM
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Keep an eye on your water heater's T&P valve. Normally they work and don't leak until you test them. Once you've broken the seal many have a slow drip and need to be replaced.

The slow 6oz/2hr movement you saw on your meter could be a slow drip. It's such a small amount that it's also within the range where water pressure and temperature fluctuations could be the cause. But with a water leak it's best taken care of NOW. Don't put it off as a water leak will do some expensive damage if not corrected quickly enough.
 
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Old 01-14-19, 05:21 PM
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I do have air chambers that were recently recharged. Would air chambers do the same thing?
To a certain extent...... yes..... those air chambers could cause that problem.
 
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Old 01-15-19, 09:59 AM
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Had a plumber come out and walked him through the problem. We bypassed the water heater and could still reproduce the problem and could verify it stopped when shutting off valve right near the water heater so it would seem there is a leak downstream from the water heater but not including it. Plumber was going to run it by his team to see some next steps for non invasive detection if possible.

May have to call a leak detection company out. Does any one have experience with that? I've heard they fill the line with a gas and have a detection tool to find it.
 
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Old 01-16-19, 03:15 PM
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Update!

I was watching the meter and saw a larger jump (.2 gallons) than I had previously saw so I decided to do a dye test on the toilets and I did find one that had a very small leak. I turned off the stop valve to the toilet but unfortunately the seesawing did not correct. I did not expect that it would since the seesawing seems to come downstream of the water heater on the hot lines. This may account for my perceived leak though or play into it.

After shutting off that toilet and watching the water meter every 30 minutes for 3.5 hours so far it seems like for the first 60 minutes of not using water the needle moved about 0.02 gallons with most of the movement in the first 30 mins. After that it appears to have settled(fingers crossed). I can chalk that up to the water settling. My previously thinking that there was a leak on the small movement may have been the toilet or not waiting long enough for the water to settle and then checking the needle.

The Utility Company is likely going to replace my meter though since the plumbers could not find any other leaks that would account for the seesaw. It did settle down a lot at the end of the 3.5 hour test so I'm wondering if it could be air chambers afterall. I tried shutting off anything electronic or mechanical in the house to see if something was causing a vibration to do this but no luck. Still odd that it stops when I shutoff water right before the water heater which would indicate its emanating downstream on the hot water pipes.

I was tempted to use a water pressure gauge to check for constant pressure over a long period of time but since it would require shutting off the water and I do not have an expansion tank it is probably not a good idea unless I buy an expansion tank to connect to the pressure gauge.

In short I'm less concerned now that I've identified one leak and turning that off, I don't appear to have any leaks. Hopefully a new meter will stabilize the flow detector.
 
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Old 01-17-19, 01:00 PM
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Possibly Resolved

After fixing the toilet flapper that was leaking and checking after things had been sitting for a while the seesawing seems very minimal. I took a 2 minute video of it and it started at the 1 o'clock position and ended up at the 11 o'clock position, every so slightly moving back and forth. This is much better than before, it was making swings of 90-270 degrees previously.

I think the clogged single handle cartridge on the hot side may have been causing it because it seemed to really stabilize after that as well. Perhaps it was letting water/pressure communicate between the hot and cold in minimal amounts.

I got my water pressure gauge in today and connected it leaving the system open to the meter and I could see slight pressure variations(less than 1 psi). Could be meter or could be pressure coming to the house. Perhaps someone a few houses down from me is having some pressure issues or a leak.

I have not heard back from the utility company on replacing the meter but I'm not going to push them on it. My thinking is if they come out, they'll check the meter again and decide what to do and if they don't it seems resolved.

Hopefully this series of threads helps someone else that runs into a similar issue as I found quite a few unresolved forum postings by others having a similar issue.
 
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Old 01-17-19, 03:38 PM
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All water system's pressures change throughout the day and then there are minor pressure pulses.
 
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Old 01-17-19, 03:42 PM
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Originally Posted by Pilot Dane
All water system's pressures change throughout the day and then there are minor pressure pulses.
I'm starting to see that. Mine seems to pulse more than my neighbor's that's in the same box but theirs is a triangle and mine looks like a gear so it may just be easier to see mine move or my meter may be a little more sensitive. We have different brands. Mine is a badger and theirs is a Neptune.
 
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Old 09-26-20, 10:06 AM
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Solution to this issue

So I had the same issue as you described. My water meter was seesawing back and forth and I believe I was being charged $$$ because the water meter only counts in 1 direction. This was verified as I didn't use any water 1 night but it metered registered like 8 gallons used. I isolated the problem to the water heater by shutting off the input valve that goes into it. I already had a water thermal expansion tank but I suspected it wasn't working properly. My expansion tank sits between the water valve for the water heater and the water heater itself . Steps I took - (1) used a tire pressure gauge with all valves open (normal) to get house pressure - it was 53 psi. (If water comes out during this step it means your expansion tank bladder is punctured and the expansion tanks needs to be replaced) (2) turned off valve to water heater and ran hot water in a nearby sink until no water came out (if your expansion tanks sinks elsewhere you may need to turn off you main water valve) (3) retested pressure in expansion tank - it was 17psi (too low!). (4) used a bicycle pump to increase pressure in expansion tank to 50 psi (5) opened the water heater valve back up. Success! No more moving triangle on my water meter. I calculated I was paying over $100 per year for this issue.
 
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Old 09-26-20, 10:20 AM
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Glad I'm not the only person. I suppose I never did update this. I ended up having two separate positemp type valves that seemed to allow minor amounts of water to pass from hot to cold or vice versa. My kitchen sink was the major culprit but also master shower. In my case replacing those fixed it.

I don't have an expansion tank or back-flow preventer (not code or common in my area).

With that said, as the water in my house cools down or heats up, it does slightly move the needle as water pushes or pulls from outside but that settles down over a few hours and its minor. I think I calculated it to about 12 oz.
 
 

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