Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

pressure regulator vent tube

Tom777 Member Posts: 1
I just replaced my old furnace gas valve ( it was a very old set up with pilot direct from gas line and separate thermocouple valve, gas pressure regulator and gas valve). I replaced the 3 valves with a robertshaw gas valve #720-406. I can't find a vent tube for the pressure regulator vent. My paperwork with the valve says it is tapped 1/8 inch tubing. Do I need it? If yes, where can i get it? No one seems to have it around here.I am assuming it would vent like the old regulator, right next to the pilot flame would be the termination point and the old tube was 1/4 inch and has an oriface of some sort at that end.  Tried home depot and grainger, no luck. Thanks for your help.


  • icesailor
    icesailor Member Posts: 7,265
    Vent tube question:

    If you had to ask that question, you probably shouldn't have changed the gas valve yourself. You may not have the expertise to have done it.

    Depending on the input of the old gas appliance, it may have needed some of the things you replaced.

    The vent is probably tapped for 1/8" NPT and most would use a 1/4" flare X 1/8" NPT adapter that will connect 1/4" OD copper which is 1/8" inside diameter.

    If you found an unexploded bomb while digging in your cellar, would you try to disarm it yourself or call experts at bomb disposal?
  • Bob Harper
    Bob Harper Member Posts: 932
    get professional help

    This is not DIY work. Get a pro before you blow yourself up.

    That valve is a gas combination valve. The regulator on it has a vent limiter so it does not need a vent line. However, if you have a medium pressure regulator upstream of this appliance and inlet pressure above 1/2psi you may need a vent line off the regulator. A pro needs to do this. You are in way over your head here.

    If the furnace used a separate gas line for the pilot it is old enough the entire unit should probably have been replaced, which would settle your issue.
This discussion has been closed.