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Makeup water meter going backward??????

elfie Member Posts: 264
here is a curious situation

a newly installed meter on a hot water boiler makeup water line is going in the wrong direction.

the basic stuff between the meter and boiler (ie. check valve, pressure reduction valve) is all OK and the flow direction arrow on side of meter is correct

also, the manual says installation on a vertical pipe is fine


  • furnacefigher15
    furnacefigher15 Member Posts: 514
    gravity flow?

    What happens if you feed water into the boiler? Still run backwards?
  • elfie
    elfie Member Posts: 264
    backward meter

    yes, great suggestion

    water is under pressure and the vertical run of pipe is about 15 feet, hard to understand why there would be backflow

    and still tough to understand why the meter continues to show backwards activity
  • furnacefigher15
    furnacefigher15 Member Posts: 514
    Idle water

    Idle water heats up through conduction, and static pressure is roughly equal in all piping, but without flow in the piping from use of water, the water will move about to find equilibrium of temperature.

    Water may be flowing up one side of the pipe and down the other, opposite the rotation expected to cause the spinner to rotate. The spinners to not have gears or any major obstacle to flow within the pipe.
  • Gordy
    Gordy Member Posts: 9,514
    What furnace fighter said

    You can have convective flow in both directions inside of one pipe with no flow. Supply side of meter water is cold, and boiler side of meter is warm from boiler.
  • elfie
    elfie Member Posts: 264
    meter direction puzzle


    but water is room temp in pipe and several yds from boiler
  • furnacefigher15
    furnacefigher15 Member Posts: 514

    That's why the gravity flow may eventual stop. But water does not come in to the building at room temp. but rather much colder, especially in the winter.
  • Bob Vennerbeck
    Bob Vennerbeck Member Posts: 102
    nearly on topic of makeup water meters

    How commonly are water meters installed on domestic boiler feed lines? I've never seen one 'in the wild'.

    Is the intent to measure system capacity? - which should work fine - or to measure tiny increments of makeup water ?- which might not work so well.

    I have a meter from DLJ [ ] that I've used in other situations, and while it does register 'very low flow', it does NOT seem to respond to 'healthy drip' -

    so the next question is - when an automatic fill valve detects a need for makeup water, how much flow is there? - does it 'burp' open, or do they creep open and admit the tiny amount needed?

  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I would love to know the answer to your question.

    I called and talked with them. My question may not have been specific enough. I wondered if it could measure a leak of a gallon a year, and they said no.

    Their web site says, "There is a trickle leak indicator on the dial to indicate any flow at all"  and "Low flow indicator for flow rates down to almost drop by drop" so perhaps the tiny leaks can be found by looking at the meter as the system is leaking.
This discussion has been closed.