Install tips & recommendations for removal of horizontal 4-inch pellet vent pipe

[ChrisWNY]

In order to replace the exhaust fan on the back of my Fahrenheit Endurance-50, I need to remove the approximately 4-ft long horizontal Selkirk pellet vent pipe from the back of the furnace (I've posted photos below). The pellet vent is both foil taped/siliconed, so it's not easily removable. It's likely going to have to be cut off. I ordered a replacement "telescopic" Selkirk 4-inch pipe, which I intend on using to replace the pipe since I'm sure the existing one will be destroyed during removal (see link below - this is what I ordered).

Selkirk - 4" Adjustable Telescopic Pipe Length (Direct-Temp for Pellet)

Elevate your Pellet system with Selkirk's 4" Adjustable Telescopic Pipe Length – Direct-Temp innovation for seamless venting. Optimal performance in a sleek design, available in galvanized or Matte Black finish.

belleflame.com

Looking for some tips/suggestions for how to best go about removing this pipe - my best guess at this point is sawz-all through the pipe and rip it out with brute force? I'm not expecting this to be an easy job by any means, but appreciate any tips the community might have here. Thanks!

 

[DAKSY]

I think I’d try a strap wrench near the Tee. If you can get the cam lock to disengage at that point, the entire vent section should turn. Just make sure there are no zip screws under the tape & silicone. If there are, a magnetic hex nut driver is useful.

 

[ChrisWNY]

I think I’d try a strap wrench near the Tee. If you can get the cam lock to disengage at that point, the entire vent section should turn.

Is it generally a "lefty-loosey" type of deal on a strap wrench to disengage the cam lock? I know that pipe is siliconed internally as well so I thought that might get tricky. Thanks for the tip!

 

[ARC]

I have Duravent pipe not Selkirk I had to replace the one foot section that went out of house, rusted were it came out of thimble. My venting went adapter, 45 degree elbow 2 one foot sections out of house, clean out tee outside, 3 feet up 90 degree 1 foot and then cap. The adapter ,45 and 2 one foot sections inside were all Red RTV siliconed inside connections. My son and I put 4 strap wrenches on that 1 foot section of pipe and could not get it to release. Sawz-alled the 1 foot section off, pulled the remaining pipe off back of stove. Took it outside and we still could not get any of it separated. Ended up replacing all inside pipe including the adapter. As stated it is Duravent not Selkirk so you might have better luck.

By the way I Red RTV'd siliconed the connections on the new pipe, the old pipe lasted 18 years siliconed connections will worth the piece of mind that they will not leak or come apart.

 

[ChrisWNY]

@ARC Did you end up replacing your entire vent pipe at that point, or just the section(s) you had to remove? I know sawing through that 3-4 ft horizontal section that connects directly to the furnace outlet will likely do the job but am hoping to reconnect the Selkirk telescoping replacement pipe to the existing Tee as well as the outlet from the furnace (and not having to replace over 8 ft of perfectly good stainless pellet vent piping). I'll have to be careful not to damage the connection to the Tee.

I know the inner pipe wall is RTV siliconed because I watched the installers assemble that pipe back in 2010 when I had the pellet furnace installed...it may not be feasible to twist it apart using strap wrenches. I'll give it a try but I doubt I'll have any luck. I understand that once a pipe is cut it cannot be reconnected to new pellet vent pipe.

Here's a stick-figure diagram of my setup...

 

[ARC]

Yes I replaced all venting inside house , adapter.45 degree angle, 2 one foot lengths all RTV siliconed, none of my venting outside house was siliconed. I tried to save the adapter, 45 degree and one length of vent after I took it off but even with the 4 straps on it I could not get any of it apart.

 

[ChrisWNY]

Well after peeling away several layers of venturi foil tape, I found the 3 small screws that were securing a 3-to-4 inch adapter to the exhaust vent out the back of the Fahrenheit Endurance-50. Once I removed the screws I was able to pull the adapter free from the horizontal 3-ft section of 4-inch Selkirk piping. I removed the entire exhaust unit and replaced the exhaust motor, which is 100x quieter (and more powerful) than the OEM exhaust fan. I had to remove the 10-inch return duct or it would've been impossible to gain access to anything on the back of the unit. Took a few hours but project finally done.

I ended up not having to pull any of the piping apart. I only used foil tape on the seams once I reattached the adapter to the pipe so it's easier to take apart the next time around. The telescoping pipe was also way too large...the inner pipe was 4-inches but the outer was over 6-inches in diameter, so I sent it back for a refund.