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hot water boiler 2 PSI

So, with the help of a plumber friend who did remote diagnostics (he's slammed with no heat calls & couldn't come by), I discovered low water in my system as the cause of much slamming, banging, and water gurgling. Not sure why make-up water wasn't introduced into the system. Valve was open.

As shown in pic, not a sophisticated filling system. Besides troubleshooting the valve, I obviously need auto filler and LWCO. And a new pressure gauge b/c the built-in on the ol' Burnham is long gone. Anything else come to mind from the experts?


  • JohnNY
    JohnNY Member Posts: 3,244
    That's a Fill-trol.
    Here's the replacement:
    You're welcome.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.
  • WMno57
    WMno57 Member Posts: 1,386
    You can add water to your system through the boiler drain valve. Use a female to female washing machine hose. Add garden hose if needed to get to a domestic water spigot.
    I DIY.
  • JimP
    JimP Member Posts: 87
    Remove the bladder tank and check the pressure at the air inlet. Fill it to a common level (12-15 lbs.). The bladder tank might be okay and the fill valve will work fine when you put it back on. If the tanks bad it will be full of water and very heavy.
  • hot_rod
    hot_rod Member Posts: 22,341
    You have a Fil Trol tank and valve. The fill valve is built into the brass fitting. It's probably stuck.
    Not my favorite set up and it takes a special tank.

    Ideally you should have backflow preventer also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    EBEBRATT-Ed Member Posts: 15,737
    For now leave the water shut off. use a garden hose with a female adapter to fill the system through the boiler drain to 12-15 psi as @WMno57 said.

    Also get a 0-30 pressure gauge with a hose adapter fitting on it to install on your boiler drain to check the pressure against the boiler gauge
  • Dave Carpentier
    Dave Carpentier Member Posts: 603
    I had trouble with system pressure at the start of this season. The good folks here pointed out that I have a Fil-Trol. With a spare port on my manifold open, I whacked the fil trol brass piece a few times and black water came out at the manifold port. Then the system pressurized properly. I think I just vibrated the crud stuck on the Fil-trol inlet screen so that enough of it flowed thru and cleared the screen (a little). Not a "fix", but it got me going.

    30+ yrs in telecom outside plant.
    Currently in building maintenance.
  • SomeTradesJack
    SomeTradesJack Member Posts: 17
    Thanks for the input. I had previously purchased a screw-on gauge, which is how I found the 2 PSI reading. I constructed a female-female hose to fill and filled from other boiler (I know--not ideal because of putting the crud from one system into the other, but other boiler has fast fill setup).

    However, both boilers lack backflow prevention (probably wasn't code back in the day). From what I've been reading on here, looks like low water cutoff is also in order. Two old systems, with 2-1/2" cast iron pipe that really feel great when you hit your head against one.

    Tank is actually a Fill-Trol 110. I'll take it off and see what I get. And how heavy it is.