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Replace a Combo King Fill Alarm/Oil Gauge

cliff10 Member Posts: 3
I have a 275 gal. vertical oil tank. Want to do one of two things. 1st to swap out the old one and replace with a new one do I have to undo all fill piping that attaches to the top of the gauge before removal? Or to make it easier and not touch the pipes, since it is just the float that does not work but, the whistle works fine, the float just stays on bottom now, when you pull up on it, it just sinks, can I use the unused hole for one of the newer Wi-Fi oil level units?
The tank has 3 holes. 1st has the combo whistle/oil gauge, 2nd middle hole the vent pipe, and 3rd is unused.

9the float stays on bottom


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Are you asking how to replace the gauge/whistle, or are you putting in a new tank.
    I would recommend hiring a professional or at least get onsite advice to make sure you install to code. You also have to properly dispose of the old tank and pull a permit.
    If you’re putting in a new tank they will have 4 bungs. Best to put in a separate gauge. On the vent pipe put the whistle and a union. Has to be all steel pipe, no copper. 1 1/2” minimum, vent same or bigger than fill.
    I recommend you have at least have your oil company check over the install and have someone watching the tank and piping during the first fill.

    You can use the unused hole for another gauge if the whistle works fine. Depending on the type, just make sure the movement of the new one doesn’t interfere with the old one.
    HVACNUT Member Posts: 5,828
    If your keeping the existing tank, for a while anyway, if the whistle works on the combo then just leave it. Install your WiFi gauge in the third 2" tapping. As long as the float doesn't interfere with the new gauge sensor.
  • cliff10
    cliff10 Member Posts: 3
    I was asking how to replace the existing comb alarm/gauge. What part of the fill pipe do you have to dismantle? Also, since it is only the float that does not work, but the whistle works fine, maybe I should leave well enough alone and put in one of those WiFi
    units in the unused hole? The float only stays at the bottom of the tank and does not float anymore.
    EBEBRATT-Ed Member Posts: 15,512
    edited October 2019
    Again, if the Wifi sensor does not interfere with the existing gage the put the wifi in the spare tapping.

    The pipe connected to the whistle/gage is your vent pipe. The other pipe is the fill pipe.

    The other way is to remove the vent pipe starting outside the house and remove and replace the whistle/gage

    you would need at a minimum (2) 18" pipe wrenches and maybe some cheater pipes
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    edited October 2019
    If your vent line has a union, from the union to tank. If it doesn't you can either cut a section so you can replace it with a union, or dismantle, reassemble the whole vent pipe.
    If you want to leave it alone and add the wifi gauge to the unused hole, we both stated that would be fine if it doesn't interfere with the existing float and it's attached linkage.
  • cliff10
    cliff10 Member Posts: 3
    Thanks Everyone!
  • trayschoice
    trayschoice Member Posts: 1
    Does the vent hole stay open on the combo?