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Shut off valve -Caleffi auto feed

northernsoul
northernsoul Member Posts: 134
in Gas Heating
Hello

I had a Caleffi 553 Autofil valve installed on my gas boiler and set at 19 psi in the summer to replace the old faulty one. I think that might be too high given my house is maybe 20 feet from the water valve to top of highest rad. My question is for the shut off valve on the back of it - is that supposed to be opened or closed and I turn towards the + or - ?

Thanks

Comments

  • northernsoul
    northernsoul Member Posts: 134
    Thanks
  • hot_rod
    hot_rod Member Posts: 22,120
    The bottom know is just a shutoff, keep it all the way open, + direction. Set the desired fill pressure on the top dial. 12 psi is the typical fill pressure, the valve and most expansion tanks are preset to 12psi.

    Always check the expansion tank pre-charge pressure, the listed pre-charge is not always what is in the tank. Do this before you connect it to the system.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • northernsoul
    northernsoul Member Posts: 134
    > @hot rod said:
    > The bottom know is just a shutoff, keep it all the way open, + direction. Set the desired fill pressure on the top dial. 12 psi is the typical fill pressure, the valve and most expansion tanks are preset to 12psi.
    >
    > Always check the expansion tank pre-charge pressure, the listed pre-charge is not always what is in the tank. Do this before you connect it to the system.

    So I adjust the set psi using a screwdriver on the guage and then close the shutoff valve all the way to +?

    Is 19 far too high ? Will that cause issues ?

    Thanks
  • hot_rod
    hot_rod Member Posts: 22,120
    Some folks leave the valve on, others prefer to leave it off. If you do leave it off, CCW direction be sure you have a low water cut off safety on the boiler, should it ever develop a leak.

    Watch the pressure gauge when the boiler is at its highest temperature, as long as it stays below 26 psi you should be fine. most boilers have a 30 psi safety relief valve to protect from excessive pressure, you don't want that to go off unless needed.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • northernsoul
    northernsoul Member Posts: 134
    So I fired up the boiler set at 19 today (first time this season since a new feeder valve was put on) and the pressure was running around 23 on the return dial after 30 min.

    I shut it down and set the pressure back to 15.

    Should that lower the run pressure when I turn it on again or will I need to let pressure out of the system somehow ?
  • hot_rod
    hot_rod Member Posts: 22,120
    Why the 19 psi pre-set, typically 12- 15 psi is used.

    Nothing wrong with 19, as long as you pre-charged the expansion tank to that pressure also?

    Also, 23 should not be a problem if that is where it settles in what at boiler high limit.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    northernsoul
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,002
    edited October 2018
    No, it won't necessarily drop the pressure in the system automatically, but keeping the water pressure at 19psi won't adversely affect anything.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    northernsoul
  • northernsoul
    northernsoul Member Posts: 134
    > @hot rod said:
    > Why the 19 psi pre-set, typically 12- 15 psi is used.
    >
    > Nothing wrong with 19, as long as you pre-charged the expansion tank to that pressure also?
    >
    > Also, 23 should not be a problem if that is where it settles in what at boiler high limit.

    The heating company filled back up the system and set the valve at 19 back when they installed it in the summer.

    I don’t know what they charged the tank to - it’s an old metal tank (maybe original from the 30s)- they didn’t say.

    I was just worried the pressure would keep climbing once the system hit full running temp and setoff the release valve
  • northernsoul
    northernsoul Member Posts: 134
    > @Alan (California Radiant) Forbes said:
    > No, it won't necessarily drop the pressure in the system automatically, but keeping the water pressure at 19psi won't adversely affect anything.

    How do you lower the pressure then to 12-15?

    So what does adjusting the feeder valve gauge with a screwdriver myself do?
  • hot_rod
    hot_rod Member Posts: 22,120
    Yes you can back down the adjustment to reduce the fill pressure, and drain some water out to lower the pressure. The fill valve cannot let water out to lower the system pressure.

    Depending on what type of expansion tank you have, it too may need to be adjusted, post a pic.

    If you drain too much water you may get an air lock in the system.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    northernsoul
  • northernsoul
    northernsoul Member Posts: 134
    > @hot rod said:
    > Why the 19 psi pre-set, typically 12- 15 psi is used.
    >
    > Nothing wrong with 19, as long as you pre-charged the expansion tank to that pressure also?
    >
    > Also, 23 should not be a problem if that is where it settles in what at boiler high limit.

    So the boiler has been off for a few hours and the psi gauge on the boiler is still showing around 20

    Shouldn’t that drop now that I’ve set the auto feed valve to 15 and it’s cool?

    Does this mean I need to release water from the expansion tank to lower pressure?
  • northernsoul
    northernsoul Member Posts: 134
    > @hot rod said:
    > Yes you can back down the adjustment to reduce the fill pressure, and drain some water out to lower the pressure. The fill valve cannot let water out to lower the system pressure.
    >
    > Depending on what type of expansion tank you have, it too may need to be adjusted, post a pic.
    >
    > If you drain too much water you may get an air lock in the system.

    Here is a pic of the tank

    Thanks
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,002
    Please read this before we continue:

    https://heatinghelp.com/systems-help-center/troubleshooting-air-and-compression-tanks/
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab

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