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Even Slow Drips Add Up Over Time

EricPeterson Member Posts: 215
At the start of the heating season I installed
  • Airtrol ATF-12
  • Caleffi 280 Mixing Valve
These have both performed exceptionally well, as the accumulation of air in the top of the system no longer occurs, and the return temperature of water to the boiler is now regulated.

However in the installation process, the near-boiler piping did have some very minor leaks - an occasional drip, and some moisture visible at some of the fittings. I was not overly concerned as I monitor the status of the boiler on a regular basis as it is right next to my basement workshop. This is something I planned to address after the heating season.

Over time I noticed that the system pressure would slowly drop, and also that that I now had the opposite of a water-logged compression tank.
That is to say, the water level in the compression tank was ever so slowly going down. I could tell by lifting one end of it slightly to gauge how full of water it was.
Also it was taking longer to bring the pressure back up which I was doing with a bike pump and a Schrader valve fitting on the tank. It was taking longer (more pump strokes) because the volume of air in the tank has increased.

I confirmed this today by using the ATF-12 to bring the water back up to the proper level.

So slow drip by slow drip I lost quite a few gallons of water over the past six months.
This seems to me to be the proper explanation for what I have observed.



  • Jamie Hall
    Jamie Hall Member Posts: 23,322
    One normal sized drip every 10 seconds or so is a gallon per day... they do add up!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EricPeterson
    EricPeterson Member Posts: 215

    One normal sized drip every 10 seconds or so is a gallon per day... they do add up!

    Ain't it the truth.

    Six months works out to 180 days, my tank is 24 gallons, and IIRC it should be 2/3 full of water which would be 16 gallons. A drip every 10 seconds would be 180 gallons so obviously that was not the case.
    Supposing though 8 gallons were left, so I think that would work out to a drip every 40 minutes. That seems possible since a lot would evaporate when the pipes are warm.
    I'll get this all fixed during the summer!