Can You Use a Water Meter to Detect Leaks? YES!

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A water meter is a great first defense tool for detecting leaks in your supply plumbing system. Many of us already have them and, for large to medium leaks, they easily detect there is a problem with the leak detector.

They come in a variety of shapes, such as a triangle:

Or a star:

Whatever the shape, they all serve the same purpose: helping you detect a leak in your supply plumbing lines.

The leak detector is the most sensitive part of the water meter, giving you a better sense into how fast water is flowing into your house, rather than just looking at the main numbers or dial.

How to test for a leak using a water meter leak detector:

At this point nothing should be running in the house. Not even the ice maker.

If the meter is outside, carefully open it…

and clear away any cobwebs/dirt to make this effort seem a little less creepy.

Leak Test #1: Is the leak detector spinning on the water meter?

If it is, skip the rest of the tests and move on to….

If not…

Leak Test #2: Take a picture of the water meter and come back in 15 minutes.

Did the leak detector move?

If it is, skip the rest of the tests and move on to….

If not…

Leak Test #3: Continue test #2 and come back at some indeterminate longer period of time, but before someone flushes the toilet.

You and I aren’t plumbers so we don’t get paid by the hour. Any time you’d like to devote to this test is worthwhile. However, this is still a very nebulous test at this point (I have no idea how much water is stored in my system or yours) and one where a small leak will not be caught.

If your leak detector moved:

1. If you are like me where the water meter is by the road and the stack going inside is on the other side of the yard with a shutoff, go ahead and turn the water off at the shutoff. If the meter continues to turn you know the leak is somewhere in your yard.
2. If there is no movement try turning the shutoff at the water heater, eliminating leaks in the hot water line.
3. Shut off any other points including under sinks, toilets and hose bibs.
4. On a trunk and branch plumbing system, that’s about the best you can do without calling in a forensic plumber, unless there is some obvious sign, which then, of course, you wouldn’t need to look at your water meter…

If you have a smart meter you may not have a leak detector, but the digital readout goes to the hundredths of a digit, giving you quite a bit more accuracy than one of the older models. Another huge benefit of smart meters is an automated surveillance of the incoming water: you can sign up for notifications to get an alert if a leak is detected.

Sample smart water meter.

**However, it is important to note, this is just a notification–not that the city would shut your water off. If you want that kind of service–leak detection and the ability to shutoff–you might want to check out a whole house water monitor and shutoff system.

That’s great and all, but what if I have a *really* small leak?

Another method is necessary.

I tested my own water meter and plumbing “creating a leak” in my kitchen faucet with a drip every 2 seconds over the course of 8 hours (when no one was getting up in the middle of the night–or agreed not to flush the toilet and use hand sanitizer). This was because the one hour test, which resulted in one cup of water in the measuring cup, did not move the meter enough to be easily noticeable.

Leak with a drip every two seconds results in one cup of water wasted in one hour.

At my kitchen faucet, a drip every two seconds results in one cup of water “wasted” (collected and used to water the basil outside). Over 8 hours that is 8 cups, which made the leak detector turn about 1/8. Interestingly enough, it  did not impact the numerical reading or the rotating arm!

The location of the leak detector on the water meter before the 8 hour test began.

The location of the leak detector on the water meter after 8 hours with the kitchen faucet dripping every other second.

Did you notice pest control peeking out in the last picture?!? He scared the heck out of me when I opened the meter box in the morning AAAAND he made a guest appearance in the Wyze timelapse in an upcoming video.

Judging by the drip every other second, you *may* notice a change with a drip every four seconds over the course of 8 hours.

It’s doable, but let’s step back a moment.

My 5-year-old and I laid out signs to make this test happen. This is, admittedly, crazy!

8 hour water meter test prep. The hand sanitizer was strategically placed in front of the sink.

Just in case it was too difficult to read “don’t flush” in the middle of the night there is a picture of a toilet crossed out!

Who is really going to go to this extent more than once a year?

Is a year even reasonable?

Probably not.

But think of the implications. 1 cup an hour is 1.5 gallons a day. 1.5 times 365 is 547.5 gallons a year. Wasteful, yes, but what if it is happening a bad spot and you don’t notice it?

Still, you have to have a real gut feeling to go this far down the rabbit (lizard?) hole.

The good news is there are other more sensitive methods such as a water pressure gauge (another manual, yet very cost effective test) or a whole house water monitor (24/7/365 CYA coverage, but $$$).

The good part about this method is it does not depend on the amount of plumbing in your house. A water meter is just using the amount of water going through the unit. In contrast, a water pressure gauge test is very much depending on the volume within your system. Big house = less effective.

If you are interested in seeing this work “in person” check out the following video. The best part part? Anything that has a purple water meter has to be somewhat fun too!

Cinematic purple water meter! –my DIY physical version of a “film burn”

How to better pinpoint a leak and the leak results will be in a follow-on video.