Pellet Stove Installation Question

[Allust47]

Hello all,

I have a pellet stove to install, and I was hoping to use an existing hole that is already in my wall from an old propane fireplace. I have the pellet stove thimble in place, and I have the vent piping on the outside hooked up and the pipe going through the thimble. The problem is, my pellet stove sits higher than the thimble in that the exhaust hookup on the back of the stove is slightly higher than the pipes leading out the wall.

My question is, is this acceptable, or do I need to find a way to either raise the thimble in the wall, or get the stove lower? I'd estimate it's maybe 1/2" difference but could be a little more. My friend said that if the venting isn't even height, smoke could pool during start-up and seep out of the seams, especially where the part coming out of the stove is higher than the rest of that horizontal run.

Any insight would be greatly appreciated.

Thanks

 

[DAKSY]

Technically, you never want to run vent downwards, but you can always give it a try & see if it's gonna run ok.
It is a forced exhaust, but it may leak, but silicone or aluminum tape keep the smoke contained...

 

[Harvey Schneider]

It may trap condensates at the low point, restricting air flow.

 

[Allust47]

I connected it to the stove and fired it up to give it a whirl, and I did put some tape on the joints on the 45 and 90 elbow, and quite a bit of smoke still came through. I'm also concerned that perhaps the draft isn't enough since i have a 45 and a 90 degree elbow on the inside. I needed both of these in order to reach the existing thimble. I suppose my only option is to either lower the stove by using a thinner hearth pad, or put in a new thimble just to the left so I can use only the 45 degree elbow and eliminate the 90, as well as ensure the exhaust has a slight rise. A lot more work than I had hoped since I had an existing thimble in the wall already but I'll do it if I must

 

[alternativeheat]

I connected it to the stove and fired it up to give it a whirl, and I did put some tape on the joints on the 45 and 90 elbow, and quite a bit of smoke still came through. I'm also concerned that perhaps the draft isn't enough since i have a 45 and a 90 degree elbow on the inside. I needed both of these in order to reach the existing thimble. I suppose my only option is to either lower the stove by using a thinner hearth pad, or put in a new thimble just to the left so I can use only the 45 degree elbow and eliminate the 90, as well as ensure the exhaust has a slight rise. A lot more work than I had hoped since I had an existing thimble in the wall already but I'll do it if I must

I think you have your answer. You don't want horizontal 90's anyway. And try to keep your horizontal flow down to 2 ft or less. If need be put in a vertical of 5 ft or so. The vertical will give you some natural draft.

 

[TimfromMA]

I think you have your answer. You don't want horizontal 90's anyway. And try to keep your horizontal flow down to 2 ft or less. If need be put in a vertical of 5 ft or so. The vertical will give you some natural draft.

Vertical rise is not required. My vent is 100% horizontal, 3 - 4 feet long and works flawlessly.

 

[Harvey Schneider]

Vertical rise is not required. My vent is 100% horizontal, 3 - 4 feet long and works flawlessly.

It is true that most stoves will draft just fine without a vertical rise. Depending on the geometry of the vent a rise might assist flow during normal operation, but it isn't a sure thing.
The advantage of having a vertical rise is that it continues to draft in the event of a power failure. Without the vertical rise it is posible for smoke to come out the air intake ports during a power failure.

 

[alternativeheat]

Vertical rise is not required. My vent is 100% horizontal, 3 - 4 feet long and works flawlessly.

I find my statement to be basically true but each stove and install is different. I did say "if ", I did not say must. I'm glad with your stove that 4 ' of horizontal works well though ! Do you have 90's in your 4' of horizontal ?