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Weil-McLain draft hood- what part #??

Bucky Member Posts: 47
Hey all, gas company did their occasional inspection at mom's house and shut 'er down since the boiler didn't have a draft hood. (long story, but it's possible that a ripoff "chimney cleaning" company removed it recently, but that's TBD). Anyhow, went to my local supplier, told them I need a draft hood for a WM CGM-5. They got Weil on the phone from NC, ordered the part, yahoo! Now the hood comes in, I disassemble the existing pipe, and go to put this thing on...and it's too big. The bottom pipe is 7"- everything installed now is 6". (Interestingly the discharge from the hood is 6", so it will easily attach to the existing flue pipe). I google like crazy, and every WM catalog I find specifies 450-021-243--which is exactly what they sent!! I double check the plate for the model number- yep, CGM-5. Double check the box- yep -243. But why is the part 7" and the boiler collector discharge only 6"?

SO, two questions: does anyone know if WM has a 6" draft hood for the CGM?

And, at the Big Box Store (distributor was closed by this time) I did find a 7"x6" "reducer"; which I could install easily enough...but the top (7" side) is a flange and not crimped, and not really conducive to a home-made crimp, what with the rolled edge and slightly wider opening to readily accept a non-crimped 7" pipe. But I have reservations installing it at that orientation with a male end going against the flow pattern. I guess I should just goo the crap out of the joint and then tape it, but would prefer not too. So the question is, does this sound like a good solution or should I hold out for the correct hood or the correct type "reducer" fitting??



  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    Never heard of a CGM.
  • Bucky
    Bucky Member Posts: 47
    Hi Robert, seems to have been a pretty popular model (now discontinued). This one was installed around 1990 or so. It's part of the 'CG' series with "P-CG" being one of the derivates. when deciphering the model names, this is from a WM doc (where the P-CG model numbers are in chart): "Delete "P" for assembled boiler without circulator and Fill-Trol. Delete "P" and add suffix "M" to designator for package unit without Fill-Trol (example CGM-3.)" Here's a link that shows all the docs for the discontinued boilers, including the CGM series:


    Interestingly, that made me realize that there were six different series of the CGM line. The docs for the six series on that link all contain chimney size in an "engineering data" table at the end of the doc. All six versions, however, list the CGM-5 as 6".
  • Bob Harper
    Bob Harper Member Posts: 977
    WM typically uses draft hoods with a 7" appliance collar necked down to a 6" vent connector pipe. The draft hood could legally be replaced with a bullhead tee to double acting barometric damper, which would allow the use of a spill switch for protection. Run it by your AHJ. Any tech certified by the National Comfort Institute should be capable of making this improvement then performing combustion analysis to ensure proper operation.
  • Bucky
    Bucky Member Posts: 47
    Thanks all, just got a response from W-M...they no longer make the 6" draft hood for this. Wish they wouldn't list the incorrect one in their docs though!! They recommend just buying a generic 16" and making sure the clearances (13 3/4" from the boiler top to the draft hood bottom) are the same. I already fudged it together with a reducing collar (ensuring proper clearances)...wonder if I should go back and do it without the extra piece in there...
  • kcopp
    kcopp Member Posts: 4,187
    I would just get a 6" standard vent hood. You are not supposed to modify a vent hood in any way...
  • Gordy
    Gordy Member Posts: 9,537
    My CGM 7 has an Eklay barometric damper.