Installed a 50k natural gas Mr heater Big Maxx . The local supplier I bought the horizontal B vent from sold me a round termination cap that you'd use for vertical, and stated that's what everyone uses for horizontal vents. Theres no evestrough above and with the upward vent slope I get dripping water from rain or snow melt. I fashioned a small piece of alum flashing over the screen part but still a small leak coming inside. Can I replace the cap with an elbow or any suggestions?
Rainwater coming in Mr Heater horizontal
- Thread starter Cochise
- Start date
nehog
Well-known member
Why is this sloped upwards?
A downward slop is typically used to allow condensation to drain out the end and not back into the heater.nehog
Well-known member
The manual is unclear about upward rise, but does address this issue:
The manual doesn't specify the direction to measure the rise. Their directions ****.
The Manual said:
The manual doesn't specify the direction to measure the rise. Their directions ****.
jethrodawg
Well-known member
Pretty sure that sloped line needs a condensate drain line on it.....
The manual has drawings that show it sloped upward. Here the code was a single wall pipe from the heater into a b vent double through the wall. It leaks where the double wall joins an adapter to transition it to the single wall. The drain line would have to be in the double wall which they tell you not to pierce ( the pieces lock together ). Maybe I'm over engineering it. I'll try a 90 deg elbow up outside and the cap on that.
dave67fd
Well-known member
To the OP, Your vent is installed correctly (regarding to the upward pitch). You need a rain/wind termination cap.
Mine has had snow buildup and driving rain. It's even mounted on a northeast wall and have never had any water entrance issues nor do I recall seeing any posts on the issue.
Mine has had snow buildup and driving rain. It's even mounted on a northeast wall and have never had any water entrance issues nor do I recall seeing any posts on the issue.
I would do the same.
Rockhead261
Well-known member
^ This, and only this. No 45, no downward pitch, no condensate drain... A horizontal termination cap is all that is needed here.
http://www.woodlanddirect.com/Direc...590912_a2s__a3a__a2s_2592250#259Sizes:5"_x_8"
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nehog
Well-known member
One must wonder why you are suggesting exactly the opposite that the manufacturer requires!
Read my post above, with the direct quote from the installation instructions...Rockhead261
Well-known member
One must wonder why you are suggesting exactly the opposite that the manufacturer requires!
The manufacturer wants to protect its equipment from corrosion at any expense. Unless we're talking about a 96% efficient condensing furnace (and we're not), a drain line on a flue is nothing short of a band aid. It doesn't fix the problem. I've installed hundreds of power vented natural gas furnaces and have never installed a drain on the flue. B vent + proper pitch + proper termination = no need for drainage.
dave67fd
Well-known member
One must wonder why you are suggesting exactly the opposite that the manufacturer requires!
Do we really need to reargue this point AGAIN?
YES IT DOES.
4. The vent must maintain a ¼” rise per foot of slope upwards
toward the termination.
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