How to connect vent to Big Maxx 45jk?

[badtomatoes]

Hey guys,
I am having one helluva time trying to connect the venting to my 45k Mr Heater Big Maxx. I've bought all sorts of vent fittings to connect to the back of my machine and nothing seems to work.

A guy from Home Depot gave me an adapters piece that is like a single wall to B vent adapter. I think it was called a "draft hood". It fits around the metal exhaust pipe coming out the back but there is quite a gap all the ay around. It doesn't seem like it should be that way. Nothing I've tried fits tight, or even snug for that matter.

Any input?



Thanks in advance.

 

[notme_76]

the bvent will fit right to the adapter fitting that came with your big max and plug directly into the flu hole in the back no other fittings needed

 

[badtomatoes]

I tried that already and it seems "loose" and definitely not airtight, not even close. Is that normal?

With all of the other things I've had to do, (trench across yard, tie into gas from my house, electrical, etc) it seems crazy that I'm hung up on this...

 

[Kevin54]

If it is a forced exhaust it does not have to be airtight. If it is not forced exhaust, say as in a water heater, it has to surround it but not be airtight as the gases will rise, but your flue would also have to rise and not vent exactly horizontally out. If you look at your gas water heater (if you have one) you will see a standoff where it lets fresh air in and up. the draw along with the gases make it go up.
If your fit is a little sloppy, not a problem, just put a self tapping screw or two in it to hold it on.

 

[jgump]

I have a 75K.

I used high temp RTV to seal the 3 to 4" adaptor that came with it. Once dry, I drilled two holes and fastened with self tapped screws. it is tight now.

The I slipper the B vent over the adaptor.

 

[badtomatoes]

Thanks for the input. It seems a little strange that it does not need to be airtight. I know it obviously wouldn't be tight like a compressed air system or gas lines but the fit just seems sloppy.

My Big Maxx never came with a 3 to 4 inch adapter. As far as I know, it wasn't supposed to. It wasn't on the parts list anyway. At this point I think I'm just going to screw either (A) the single wall 90 or (B) the "draft hood" directly to the output, followed by the b vent through the roof.

Does this sound right?

 

[badtomatoes]

Well, the draft hood fit a little loose. I used a couple self tappers to connect it to what I think is the "flue transition" from the heater. The Big Maxx instructions leave a lot to be desired. Anyway, I think success is near.

Thanks for the input.

 

[rickairmedic]

Code says 3 screws per joint in single wall pipe as well as transition from single wall to double wall . This should be plenty to tighten up your joints.


Rick