Mr. Heater 4" Appliance Adapter

[NicksNotNaked]

Hi! I am wondering if I am supposed to use a bead of RTV silicone and just tighten the metal worm clamp around the outlet of the heater? There are no screw holes as shown below. Working with a Mr. Heater 50k unit so this is all 4" stainless since I am doing a horizontal vent install.

 

[gmcgeo]

that looks like a Saf-T Vent Category III . and if it is here is the exact quote from the manufacture

• Engineered with laser welded seams for leak-proof installations and a factory-applied silicone gasket (no RTV sealant required) makes for an easy installation

 

[NicksNotNaked]

that looks like a Saf-T Vent Category III . and if it is here is the exact quote from the manufacture

• Engineered with laser welded seams for leak-proof installations and a factory-applied silicone gasket (no RTV sealant required) makes for an easy installation

So just the worm clamp? First time using this type of appliance adapter. Other types with the screw holes are sold out locally. Thanks in advance!

 

[gmcgeo]

So just the worm clamp? First time using this type of appliance adapter. Other types with the screw holes are sold out locally. Thanks in advance!

this might be easier https://heatfab.com/uploads/EZ_Seal_Catalog.pdf
By what the instructions say, it is all just stab tighten nd you are done.

 

[Gizzi]

You might need this fitting... https://www.menards.com/main/heatin...appliance-adapter/9464-1p/p-1444453722267.htm
Goes from the heater outlet to cat 3 vent pipe

 

[ShopNotShed]

Installing the venting for my 125KBTU unit and just made the decision to switch to vertical instead of horizontal. With vertical am I able to use B-Vent instead of Category III?

 

[Gizzi]

Installing the venting for my 125KBTU unit and just made the decision to switch to vertical instead of horizontal. With vertical am I able to use B-Vent instead of Category III?

Vertical allows for B vent provided your horizontal run is 75 percent or less than the vertical portion. So if you have 10 feet of vertical rise, and your horizontal is less than 7.5 feet, you can use B vent.

 

[ShopNotShed]

Vertical allows for B vent provided your horizontal run is 75 percent or less than the vertical portion. So if you have 10 feet of vertical rise, and your horizontal is less than 7.5 feet, you can use B vent.

Thank you!!

 

[grounddevil]

Piggy backing on this thread. Just got Hot Dawg 60k unit installed and used the Saf T vent from menards. I don’t think the thimble they had me get is the right one for these cat 3 vents. Is this big space okay if I just caulk or should I go back and grab the right one? Menards doesn’t look like they have all the necessary accessories for these cat 3 4” vents. Some parts they suggests to use the parts for the b vents even though they don’t fit as well as in this case.
Also I realize the T needs to be turned 90 degrees. What happens when it rains and rain water gets into the end? Doesn’t seem right that it can just backflow into the heater.

 

[Showkey]

When you use CATIII its suppose to from the unit to the cap.
The thimble is a critical component to provide air space fro the pipe to combustible materials.
The pipe is suppose to be down the center of the thimble. Pretty sure that might be a “B“ vent thimble
The CAT III is likely not suppose to be that close to the soffit ?
Those galv elbows will rust and dissolve over time.

This is the typical setup where the pipe will have about 1/8-1/4” clearance to the thimble.
That gap is sealed with the high temp silicon in the kit:

• Connects direct to unit
• Includes high temp silicone for sealing opening on wall thimble
• Material list based on average run of 5' - 7'

 

[grounddevil]

Thanks for the response.

I might have screwed up royally then...definitely admit I got over my head.
I do think you're right it's a B vent thimble. I had the guy at Menards help me find parts and because they didn't have the kit, he was reading parts of the kit and was handing me individual parts...guess he might've read the wrong part number.

The single wall part is definitely my fault for not knowing there's category III single wall. Also that hole was cut too close to the soffit so hard to get it away from it now. It's about a couple of inches away. The manual didn't have any specs over how far away from soffits.

Any tips on salvaging this?

 

[Showkey]

Could you reposition the heater to allow a straight even alignment with the current hole ? That would delete the galv elbows. They make CAT III elbows as well. Buy the CAT III thimble. Use the CAT III thimble and the B vent cover outside trim the top to fit flat and even with the siding cut back and soffit. Maybe a piece of flat galv sheet against the soffit on the outside ?

If you use the galv elbows watch them for rust. My heater was installed by a pro prior to my purchase when B vent was allowed in horizontal vent. It was very thin and rusty when i purchased the home. Replaced with the same. Two years later it was very rusty again. Then the heater failed…….replaced the heater and installed a complete Cat III.

 

[Gizzi]

Thanks for the response.

I might have screwed up royally then...definitely admit I got over my head.
I do think you're right it's a B vent thimble. I had the guy at Menards help me find parts and because they didn't have the kit, he was reading parts of the kit and was handing me individual parts...guess he might've read the wrong part number.

The single wall part is definitely my fault for not knowing there's category III single wall. Also that hole was cut too close to the soffit so hard to get it away from it now. It's about a couple of inches away. The manual didn't have any specs over how far away from soffits.

Any tips on salvaging this?

Single wall clearance to combustibles is generally 6 inches. Clearance to combustibles can be reduced with proper barrier materials but I think you'll have to blast a new hole to make it right. Thimble appears to be the wrong type, doesn't have proper clearance around the circumference.

 

[grounddevil]

I want to try to avoid another hole but if I have to then I have to. My biggest worry is how close the vent is from the soffit and if any rain water will enter the T with it not being covered under the soffit.

I can definitely purchase the dualwall cat III parts and make it cat III all the way.

The B vent thimble does have clearance as the portion inside the wall is 2" wider than the vent but yes I need to just go get the right thimble.

Thanks guys!

 

[240sxguy]

I want to try to avoid another hole but if I have to then I have to. My biggest worry is how close the vent is from the soffit and if any rain water will enter the T with it not being covered under the soffit.

I can definitely purchase the dualwall cat III parts and make it cat III all the way.

The B vent thimble does have clearance as the portion inside the wall is 2" wider than the vent but yes I need to just go get the right thimble.

Thanks guys!

I can confirm that the single wall cat III gets stinking HOT during operation. I touched it like a certified ******* after kicking it on the first time. You're going to at least discolor that soffit. And the termination should not end under the soffit either. Do yourself a favor and re-read the installation instructions if you aren't sure, they pretty clearly spell out the required clearances.

 

[Showkey]

The termination Tee can be turned horizontal per the instructions:

“Tee openings can be positioned up and down or left to right”

It should be at least 12” pass the soffit or eve.

 

[grounddevil]

I can confirm that the single wall cat III gets stinking HOT during operation. I touched it like a certified ******* after kicking it on the first time. You're going to at least discolor that soffit. And the termination should not end under the soffit either. Do yourself a favor and re-read the installation instructions if you aren't sure, they pretty clearly spell out the required clearances.

I’m gonna run single wall cat III from the heater to the thimble then double wall to the termination. Looks like how far the termination extends past the soffit won’t be a problem then. I’ll switch out the thimble and replace the galvanized parts and then I think I’ll be good