Category III Reznor Vent angle issues

[logan74k]

Hi there folks,
I'm hooking up a UDAS-60 with a horizontal concentric and trying to do it right, flying in the face of 4 professional heating supply houses around me who either haven't heard of or don't stock category iii pipe.

Anyway, I have no problem finding the 4" Z-Flex or Safe-T vent online, but my heater is mounted at an odd angle (38 degrees) and I'm not finding ANY adjustable elbows in Stainless sealed versions. Am I missing something? I believe odd angles are possible using multiple fittings, is that what I'll be needing to do in this situation?

Obviously, I'm a DIYer, totally comfortable up to the electrical side. I was hiring a pro for the gas and vent but it sounds like pros who 'get' Cat 3 are few and far between. Thanks for any tips.

 

[earlybirds]

I got my Cat III 4" adjustable elbows at Menards.

 

[logan74k]

I hate to question, but are you *sure* the adjustable elbow you got at Menards was stainless with built in seals? I don't see Saf-T offering an adjustable elbow as an option, nor am I seeing one on Menards website.

 

[earlybirds]

I used Menards SKU 6374110 four inch 90 degree adjustable elbow. It has the built in seal.

 

[logan74k]

I used Menards SKU 6374110 four inch 90 degree adjustable elbow. It has the built in seal.

Thanks for the link. The odd thing is, the spec page (11 of the Technical PDF) for that particular elbow specifically says "The degree of these welded seam elbows is not adjustable."

I get it that the point of this system is to be airtight and extremely corrosion resistant, so maybe what I'm looking for does not actually exist in that they can't make rotating seams 100% sealed. But then does that mean you can't put in Cat III rated venting unless your heater is vented vertically, or mounted exactly at one of the prefabbed angles?

Would love for somebody who really knows Category III venting to chime in if they're on this board.

 

[thammel]

I used cat 3 z flex and see your problem. Isn't there any way to change the 38 to 45 degrees? It seems that would be the thing to do. If you can't, then a couple of 22.5 degree fittings rotated relative to each other a little bit should be able to get you to 38 degrees. I will say the darn z flex is expensive and a pain to cut. i could only find it on-line. However, the whole setup works well.

I installed a 60kbtu Reznor UDAS.

Tom

 

[Jackfre]

As you know and are trying to do, proper venting is critical. My suggestion is that you call Z-flex customer service and describe what you want to do. They will help you.

 

[logan74k]

Good call Jackfre, I'll give it a shot. Seems like common sense but it's surprising the tunnel vision you get desperately trying to solve what seems like such a simple problem.

 

[pbon]

Can you re-hang the heater?

 

[Jackfre]

This is the problem with selecting a Cat III appliance. It is not high efficiency and requires a corrosion resistant "special" vent system. I haven't looked at the pricing of these things, but I know the venting material is very costly. Putting the cost of the vent into a high efficiency unit and venting with PVC or better yet Poly pipe gives you better or easier venting options. You do have deal with condensate with the high eff. units. That can be problematic if you live in climate that is very cold and you run it on/off. The simpler option if you can make the vent work is a Cat I unit and vent it with B-vent. Same efficiency as the III and a lower cost easy to handle vent system.

 

[das_V8]

Good call Jackfre, I'll give it a shot. Seems like common sense but it's surprising the tunnel vision you get desperately trying to solve what seems like such a simple problem.

Curious on the outcome of this? I'm trying to drop my horizontal concentric vent run below a bulkhead - and keep it as high and tight as possible, while maintaining 1" combustibles clearance and correct downward slope. I'm playing with a 90 and two 45s to get the right angle.

 

[6768rogues]

I used good quality galvanized vent pipe on mine and it still looks like new 25 years later.

 

[das_V8]

I used good quality galvanized vent pipe on mine and it still looks like new 25 years later.

25 years ago you didn’t have to use UL listed stainless Cat 3, now you do.


Sent from my iPhone using Tapatalk

 

[D45]

Vertical vent kit......$65, done