That said i ve never seen it happen quite that much.
Water meter leak indicator going back and forth.
If you walk out to your water meter and notice the area around it is wet and soggy or you see standing water and puddles then you have a leak with the water from the main line coming into your home.
I think it is water pressure fluctuations in the system.
There are several external signs that you can look for around your water meter to determine if you have a leak.
As pressure changes in the water main the pressure will equalize in your house causing the meter to fluctuate a bit back and forth.
When the pressure rises more water is forced into the home.
That means there is a leak between your water meter and your side of the shut off valve.
If the leak indicator or dial hand is still rotating then water is flowing somewhere between the meter and the shut off valve.
On my inspections i always look at the water meter to see if the flow needle is stopped when all the water is off in the home.
This would definitely make the meter spin backwards and warrants a call to your local plumber.
If it is moving forward clockwise there is water flow.
Today i saw something new.
If the meter is installed backwards the meter will do that.
I m not saying it is backwards just that it will act like that if there are pressure changes.
Do you have a pressure reducing valve prv.
When the pressure drops then the excess pressure in your system flows backwards again to equalize the pressures which makes the dial tick backwards.
When the pressure increases some water goes into your system to equalize the pressure which makes the dial tick forward.
If it twists slowly back and forth that can be caused by fluctuations in water pressure and is not a leak indicator.
Is the only cause of this a leak somewhere.
The flow needle was turning slowly forward then backwards stopping then forward then backwards and stopping it just kept doing that.
I looked at the meter next to it just for comparison it was stopped and steady.
So if there is a pressure build up from the street it would force water into the house and then the wheel would go backwards as the pressure equalizes.
Backflow is when water flows incorrectly in the wrong direction.
I have seen the flow indicator on older mechanical meters show a back and forth surging so i would say it s normal.
I recently noticed that the red triangle on the face of my water meter was moving back and forth by about 3 4 of a revolution.
I didn t have any fixtures etc turned on while this was happening.
Thursday june 21 2018 most water meters have a leak detection spinner in the shape of a triangle star or arrow that can show low level water flow.
Each time it moved forward backwards forward it ended up a little past where it was.
You ll often see this when someone on your block turns on their sprinkler system or a fire hydrant is opened.
Then when the pressure decreases water flows out.
All is well with your system.