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2 Pipe Heating System

ElliottElliott Posts: 7Member
edited March 11 in Heating Hell
Does anyone know how cut off the water supply to 2 pipe heating system. I removed a radiator from my cousins 2 pipe system. However, the the pipe that doesn't have the valve on it is constantly getting a small stream of water forced up through it. How do I cut off the water supply so it will stop? Any help is greatly appreciated guys/gals.


  • JUGHNEJUGHNE Posts: 4,936Member
    edited March 11
    That is the return. It needs to be capped off.

    If you shut the boiler down the water will eventually stop dripping.

    If there was a trap on that pipe, you need to remove it and put a pipe cap on the riser. A cap will not fit on the trap union.
  • ElliottElliott Posts: 7Member
    edited March 11
    Thanks. I did cap off the pipe. However, I also turned the boiler off completely and the water ran all night long. That's why I was thinking there must be a water supply constantly being fed to the pipe. What do you think?
  • ElliottElliott Posts: 7Member
    edited March 11
    I'm new to this, so maybe there is something I'm overlooking.
  • JUGHNEJUGHNE Posts: 4,936Member
    Two pipe rad, supply pipe with valve shut off. Return side with pipe cap installed. Where is the water running to?

    Or do you mean that when the boiler was off overnight the return line had a small stream of water before you capped it?

    There could be a water feeder valve in the basement at the boiler incorrectly passing water into the system when it shouldn't be. With the boiler off for at least an hour where is the level in the sight glass?
  • SteamheadSteamhead Posts: 12,410Member
    Is this a steam or hot-water system?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • ElliottElliott Posts: 7Member
    Hey guys. Thanks for your replies. I'm heading back to my cousins today to look at the system again. Since I capped on the one pipe, he stated water started leaking from radiator upstairs. I'll chime in with a report later on this evening for more advice.
  • ElliottElliott Posts: 7Member
    edited March 12
    I also believe it's a hot water heating system because there is a large tubular expansion tank that sits above it.
  • Jamie HallJamie Hall Posts: 8,924Member
    Hot water system... you have removed a radiator. Both the supply and the feed should have a proper cap on them; don't count on the valve. If it's threaded, you need to use a threaded cap and dope or tape (I prefer tape).

    Now... you also need to check and make sure that the loss of water didn't allow air to get into the rest of the system, where it can cause problems with heat. There should be a water feed -- either a pressure reducing valve or a manual feed -- to the boiler. There should also be a pressure gauge. The system pressure needs to be enough to reach the highest radiator, plus usually around 5 psi (allow 1 psi for every 2.33 feet of elevation from the boiler to the highest point, and add 5 psi). The horizontal tubular expansion tank shouldn't need to be fussed with. If the pressure dropped too low, you will need to add water -- just enough to bring it up -- and you may need to bleed the radiators.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • ElliottElliott Posts: 7Member
    Thanks Jamie. I'll be checking for all of this when I head over there today after work. I'll post my report later this evening.
  • ElliottElliott Posts: 7Member
    edited March 14
    Ok. So what I did was turn off the water supply to the heater and drained some of the water from the boiler. Problem solved. No more water being forced up pipes. The pressure even went down. My cousin will be calling a pluming & heating specialist to install new radiators and get the system back up to speed. Thanks for all of your replies!!
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