When should I be concerned about backflow?

Locally, there's been a lot of issues with extremely high water bills. People complaining of surprise bills two or three times the normal, so I went out to check my water meter and see if anything was up with mine before I got a surprise bill. Luckily, no surprises there, at least not with that.

However, when looking at the meter (and it's a digital one, not a gauge), it's counting DOWN. I am ware of what backflow is and know that can be the cause of a meter counting down, but it's soooo slow counting down. Example: 1,239.652 is what the meter read when I checked it. After a minute, it read 1,239.651. Another minute or two, and it was 1,239.650. So one thousandth of a gallon every minute or so. I assume that's very little backflow, but is it something to be concerned with? (For perspective, when I run a single sink, the meter was going up a full tenth every second)

Also of note, the county just switched from the old gauge meter to this new digital meter (looks like this one) in the last few months or so. We definitely had a different meter when I was checking on a possible irrigation leak back when we started up the irrigation system for the year.

Most meters are only accurate to +/- 1.5%.

I wouldn't go by a slight movement in a meter reading. No guarantees it's the result of actual water flow.

If you're that interested in finding out what's happening, you should try verifying if there is, in fact, backflow taking place.

Why would you be concern if there was a minute(small) backflow? Which I kind of doubt. That would mean that your house side pressure is exceeding the service pressure.

If your concerned with incoming flow accuracy, you could flow a measured amount of water and see how it compares to what the meter reads.

When you ran your sink you said, "...the meter was going up a full tenth every second". That would equate to 6 GPM. Does that sound right to you?

EDIT: Is your meter in gallons and not cubic feet? It sounds like it must be.

the meter you indicated you have has a reverse flow indicator, you should see an icon if that has bee detected
if you feel you have a faulty meter, contact the city,

You should call Badger regarding your observation of the digits slowly going backwards.
Would be interesting to hear what they have to say.

I went out and looked at it and it cycles through a few displays.

The main one (and one it stays on the longest) has the reading with a check mark on the bottom left, indicating that everything is working correctly. No sign of a backflow message.

Then it goes to another display that says "d 25 6_"

I've yet to find anything that details what that second display means. The third is a current rate (gal/min) of flow. And, when I have nothing running, it signals 0.00, although I assume it would show that even if there was a small leak or small backflow because it was so negligible one way or another.

There are no other indicators of errors with the meter, and I've had no issues with my bill (although I guess if it's clocking backward, I'd be okay with that, too), so.... for now, I'll let it go. I appreciate the feedback from you guys.

"displays the meter type, digit resolution from the encoder and unit of measure."
Whatever that means!

The best I can make out is that the "HR-E® LCD" is the Encoder/display not the meter type. There is a Model 25.???

I sent the question on display slowly moving backwards to Badger. Hopefully I'll hear back from them.

the "HR-E® LCD" fits onto a badger or equalivent water meter
it is just the head, it is not the body of the meter

frodo said:

the "HR-E® LCD" fits onto a badger or equalivent water meter
it is just the head, it is not the body of the meter

Click to expand...

Yes that's what I concluded. Thanks for the confirmation.

I asked Badger (by email),
"Why does my Badger meter HR-E® LCD readout go backwards 0.001 digit every minute or two?"

There response,
"The encoder is displaying the flow that is occurring inside of the meter. You may have some 'sloshing' of water and that is causing the meter internals to rotate back and forth and the display reflects this. HR-E LCD encoders do 'see' back flow. Other register/encoder types are designed not too. They ignore it."

So in other words that person didn't have a good answer for it.

Thermal expansion?