Mr. Heater Horizontal vent question

[catuck]

Ok, I have read the other posts, which have been very helpful. I have a different sort of problem. I would like to mount my 75000btu Mr. Heater Maxx closer to the wall than 3'. The manual seems to contradict itself. At once it states minimum 3' pipe then it states a maximum number of 3 elbows in 5'. Does min. 3' pipe mean a straight run or can I have elbows? Also, I have the vent kit with a 3' length of double walled vent pipe. Can I cut it? Or do I even need it. The manual lists a min. wall thickness but does not seem to mention the requirement for the double wall.

Any advice is greatly appreciated!

Thanks

 

[240sxguy]

Catuck, each elbow accounts for 1' of pipe. I ran dual wall pipe for the entire run on mine, which was relatively short. I read on the site that most code requires that anything past 3' needs to be double wall. Any part that penetrates a wall or runs through an attic must be double wall as well. Even if that is overkill, its relatively cheap and better safe than sorry.

I wouldn't cut the double wall. It makes it pretty difficult to reassemble. I was able to get double wall pipe in different lengths from menards/home depot. The depot was cheaper btw...

Read the instructions carefully a few times, they can be kinda confusing but they are very specific.

Evan

 

[rickairmedic]

Catuck Evan was listening and what he said is right . Code says no more than 3' of singlewall pipe this includes 90* elbows which each equal 1' of pipe and no dont cut the doublewall pipe if you need shorter sections of doublewall go to a hardware store and buy what you need .

Rick

 

[dipper]

I cut the double wall pipe but don't recommend it for a permanent installation, it would be easier to just get the size you need from the store. I will be replacing mine this summer when I re-do my vent when it's warm out.

 

[catuck]

Thanks guys, great advice! I'll take your suggestion and buy the correct length pipe. I also spoke with a tech. at Mr. Heater and he confirmed that the 3' does not have to be in a straight run.

 

[BigChevy80]

Don't forget that most codes require you to use stainless pipe for a horizontal vent installation...

 

[KnottyPine]

If the vent kit you have is also from Mr. Heater, the double walled B-vent should be a 3 foot section. This is designed to go through the wall (though the thimble) and stick out a minimum of 12 inches on the outside.

Double wall vent is used when going though combustibles and when the vent travels through non heated spaces. Double wall stops condensation problems in non heated spaces.

When 12 inches is left outside and you go through an 8 inch thick wall, this only leaves 16 inches of vent needed inside.

Hope it helps.

Dave

 

[catuck]

Thanks guys. 16" of vent inside is too much. I picked up a 18" peice, which basically terminates at the inside face of gwb. This works great and my vent is connected! Now I just have to wait for my plumber to get here and hook 'er up! I guess he needs to bring along an electrician as well due to new codes that require gas lines to be bonded if they're CSST.