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Changing vent size

Dustyk Member Posts: 1
New installation. I want to direct vent a Weil-McLain Gold . 7 " breech. Field Controls only, offers 6" or 8" wall termination kit. Can I run 6" right out the top of boiler to 6" termination? The run is 2' vertical , 2' horizontal to wall. Or is it better to up size to 8" termination kit?


  • chapchap70
    chapchap70 Member Posts: 139
    Do not downsize

    If the connection out of the top of the boiler is 7 inches, the manufacturers usually do not want the flue piping to be 6 inches otherwise they would have made it 6 inches themselves.

    Usually it is better to go up a size if you can't get the same size venting as the boiler. 
  • billtwocase
    billtwocase Member Posts: 2,385
    haven't seen one

    I would check on direct venting a Gold boiler 1st. I have only seen Ultra boilers direct vent, never a Gold series. Weil would direct you to the to the kit for it, if it can be done.  I've also never seen any size bigger than 6 inch on the exhaust input, 5 being the most common. Power venting is another story. You can go 7" down to 4-5" depending on the BTU input of the vent
  • icesailor
    icesailor Member Posts: 7,265
    Direct Venting a Gold:

    If asked to Direct Vent a Gold, I would refuse. When the problems start, I will look like a fool, trying to fix the unfix-able without Power venting.

    Like Billtocase says, if Carlin wanted it direct vented, they would sell or recommend a kit.

    An oil company I deal with has ripped out every direct vented oil burner in their service base due to problems for a Power venter or a metal chimney.
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