My Mr Heater Bigg Maxx Install

[z28dad]

There is alot of studying when it comes to where to put these heaters. I think I have maybe failed on my first attempt. Thank God I have not starting cutting anything yet.

When I mounted the heater up in the ceiling earlier this year, I was planning on venting it horizontally. I was under the understanding that I had to be 18 inches below the soffit. Where I got this from I don't know. The manual says 4ft. That's pretty much a deal killer, because I would be over the 5 ft max length. Also lowering the vent exit through the wall puts me closer to a window.

So my next option is to go through the roof, which by the way intimidates me some. The directions are not real clear about what pieces go where. Here is were it gets interesting. My builder must have had an extra truss left over. The far side of the garage where they started are on 16" center, but when it get closer to the other side where the heater is, they are just under 10" oc. I'm wondering if I will have enough clearance and air space to run a 4" vent kit through it. Also I will have to move a little wiring. That's no big deal. Here are some pics:



If I'm reading the instructions right, it states 1" of air space for 3"-24" sizes. Which I should be ok.

I originally purchased a horizontal kit. I"m thinking I will need to purchase additional items:

roof flashing:

http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

storm collar:

http://www.lowes.com/pd_373-41698-10...d=10151&rpp=48

Longer pipe:

http://www.lowes.com/pd_37418-41698-...ent&facetInfo=

Not sure if anything else is needed. I'm also concerned about the height of the pipe. The exit is on the backside of the building down towards the gutter. Its a 4X12 pitch.

I will also add that my trusses are scissor trusses, so I will have no attic access once the drywall is up.

I'm planning on contacting a neighbor of mine that runs a burner service business, but wanted to ask you guys so that I may gain some knowledge before I call him.

Let me know what you guys think. Thanks, Russ

[Freon]

firestop around the pipe. The metal one is probobly an 8x8 or 6x6 square with your round hole cut in center. Helps keep pipe centered on your 1" clearance from combustibles.
Don't think lowes has them. I know around here at least one side of a penetration has to have one.

[z28dad]

Freon, Thank you for the reply. I have been gathering parts for the install. I did see the fire stops at Lowes. I wasn't sure if I needed one or not. I may need to go back and pick one up. I might have to get creative on installing it. I made wedges to fit between the trusses to get the heater mounted level using kendorf. I can probably bend a flange on it and fasten it into the side of the trusses. I did purchase a pipe clamp for this area.

I do have a few more pics with some questions. I'm planning on using single wall 26 ga pipe coming out of the heater and then it will go into the B 90. From there I have a B vent pipe that is 5' long. It should stick out of the roof 2'. I hope it clears the peak. If not I have two more 18" pieces of B pipe.

My first question is attaching the pipe to the heater. Maybe I missed it in the directions, but what is the proper way? Right now I just pushed the adapter into the 4" pipe. I'm guessing from there a few sheet metal screws would do the trick. Is this correct?



Here is a few pics of my mock up so far:







I would like to use the B pipe all the way, but was having trouble using it with the heater adapter. I may be missing something here.

Here is a few pics of the parts I picked up. I have adjustable flashing for the roof, a pipe clamp and thimble. Not included in the pic is a storm collar, roofing caulk and caulk for the pipe. I have a regular outdoor cap, but plan on looking for a high wind cap.

Also one more question concerning the thimble. I'm guessing the scissor trusses will present another challenge. It will only be for passing the pipe through the 1/2" drywall. I'm thinking that since there is such a small amount of space between the bottom cord truss and the roof, I may not use the thimble and make sure that I keep the drywall 1.5-2" from the b pipe. I then will have to find a trim piece, probably something from a larger pipe. If I only use one side of the thimble I can angle it enough to match the angle of the truss:



Total flue length should be 6ft with a 90.

Thanks for any help. Russ

[Freon]

Put firestop on the drywall. That will assure you keep centered away from it. Then just buy adjustable rain collar that is a size larger than your bvent. Fan the collar to make a funnel shape to cover your firestop.

Couple screws to put single wall to bvent is fine.

[z28dad]

Thanks Freon. That sounds like a great idea. Here is what Lowes has:

http://www.lowes.com/pd_81349-41698-...irk&facetInfo=

I was thinking it was a firestop, but its listed as a support. What do you think about using it?

[dave67fd]

My first question is attaching the pipe to the heater. Maybe I missed it in the directions, but what is the proper way? Right now I just pushed the adapter into the 4" pipe. I'm guessing from there a few sheet metal screws would do the trick. Is this correct?

Yes, use 3 corrosion resistant screws. In addition, seal the joint with hi-temp silicone or foil tape as long as it's rated for hi-temp. For sealing the single wall to double wall B-pipe pretty much same way. See below. Of course you would normally never drill thru both walls of B pipe to join to another B pipe only when attaching to single wall.

How to connect a single wall vent system to a double
wall (type B) vent pipe:
1. Slide the single wall pipe inside the inner wall of the
double wall pipe.
2. Drill (3) holes through both walls of the single and
double wall vent pipes. Using 3/4" sheet metal
screws, attach the two pieces of pipe. Do not over
tighten.
3. The gap between the single and double wall pipe
must be sealed but it is not necessary to fill the full
volume of the annular area. To seal, run a large bead
of 400°F silastic around the gap.

[z28dad]

I want to thank everyone for there help on this install. I have worked on it the past couple of days for a few hours and here is what I have:

Measuring the hole for the cut:



Mocking it up and making adjustments. The fire stop came with a bracket that was suppose to keep the pipe from sliding down. With my ceiling being a cathedral ceiling the bracket only made contact at the front of the fire stop, so I added a couple of hangers on each side. I also put two brackets around the pipe to keep it centered in the hole. I wasn't sure if it was OK to add screws for the hangers, but I used short screws so that they would not puncture the inner pipe.



I still need to fill the gap between the double 90 and the single wall.



Next I added a couple pieces of wood so that my sheet rock would have something to bolt into.



I plan of having my drywall guys just barely go behind the fire stop.



Heater from the front:



Heater from the rear:



Pipe from the roof:





Hopefully I used the right silicone on the storm collar and at the top of the flashing. Its almost metal looking, so it looks like there is nothing there. Its not really labeled as high temp, but the label says service temp is -60-400 degrees F.

Next I have to finish the wiring and then start running the gas pipe. Let me know what you guys think. Thanks, Russ

[MichMan517]

Looks like a very clean install Russ. I'm getting ready to put it a NG 45K Mr. Heater. I'll have a much easier time than you had with the cathedral ceiling. Keep the pics coming, can't get enough.

[z28dad]

Thanks MichMan. Can't wait to get it fired up.

[NXGTS]

I'm glad you were able to sort through the issues. Now I can take all the hard work you've been through and copy it. I am going to have all the same issues as I also have cathedral ceilings. Thanks for posting the install. I look forward to seeeing the rest. Keep us posted.

[z28dad]

Originally Posted by NXGTS

I'm glad you were able to sort through the issues. Now I can take all the hard work you've been through and copy it. I am going to have all the same issues as I also have cathedral ceilings. Thanks for posting the install. I look forward to seeing the rest. Keep us posted.

NXGTS, here is a thread about mounting the heater with the scissor trusses.

http://www.garagejournal.com/forum/s...d.php?t=100185

Good luck with your install. I hope it goes smooth. I hope to get more time to work on mine later this coming week.

[z28dad]

I completed the wiring of the unit this afternoon. Hopefully later this week I can get the gas line installed.

I mounted a cooper combination switch on the wall that has a pilot light to give a visual when the heater is powered up. I'm not sure exactly if I will run the unit at all times. I'm thinking I might, but this will also act as a safety switch if something should go wrong especially since the plug is on the ceiling and would require a ladder to access it.



Next I installed a twist lock receptacle in the ceiling. I also installed the T-stat wiring.





I went round and round on where to mount the t-stat. The heater is at the back wall and on an angle toward the farthest wall of the garage. I decided to mount the t-stat as close to the farthest corner as possible. It is near the overhead door and man door, but most likely I will using the man door from the side entrance anyway. My thinking was if I had it warm in this location, the whole space would be warm. I may try it for awhile and if needed I will relocate it. My next option was to mount it behind the heater.

I had a friend give me a really nice programmable t-stat. He couldn't get it to work well with his heat pump. He actually got so aggravated with it that he had a new heat pump installed. (Kinda of a long story), so I'm going to see if it will work with this unit. It would be nice to have a programmable t-stat, although this is probably going to be like cadillac emblems on a chevette, but it was free.





I still need to find something suitable for sealing the single wall pipe to my B 90. Does anybody know how hot the single wall pipes get coming right out of these units? After that I need to run the gas line, pressure test, and then hopefully get it inspected.

Thanks, Russ

[dave67fd]

z28dad,
Beware of the programable thermostat. If it is micro-processor based it "could" cause problems with the Big Max. They recommend using an isolation transformer between the therm and heater.

Also, you might consider mounting another switch right at the heater or to the ceiling in close proximity for local service/testing, it's also code in some locals.

The Permatex Red or copper Hight temp RTV will work well. Any auto parts store will carry it. You can also get the Dow Corning Silastic but i think it's harder/more expensive to get.

Installs looking good. Nice detail on the pics.

[KCarGuy]

Nice Job so far.
I like the switch with the indicator light. (I might steal that idea)

I had a Programmable Thermostat and switched it out for a Super Simple Honeywell Unit.
It is meant for garages, because its a Heat Only Mechanical Unit, needs no back-up batteries, and can be set as low as 35 degrees.
It has an Off switch that is also nice.

I use single wall pipe off of my Beacon Morris Unit (90 straight out, about a foot over, another 90 back, through the back wall, out another 16", and 90 up three feet)
Every seam is wrapped in aluminum tape.
I can take a Temp reading on the pipe with it running if you would like.

[brddog]

Originally Posted by KCarGuy

I had a Programmable Thermostat and switched it out for a Super Simple Honeywell Unit.
It is meant for garages, because its a Heat Only Mechanical Unit, needs no back-up batteries, and can be set as low as 35 degrees.
It has an Off switch that is also nice.

Can you post a link or give the model number of this Honeywell Thermostat your talking about, sounds interesting since you can set the temp that low and its meant for garages.

[Lambo nut]

Originally Posted by brddog

Can you post a link or give the model number of this Honeywell Thermostat your talking about, sounds interesting since you can set the temp that low and its meant for garages.

Not to step on any toes, but here is a link to the one I use and posted in another thread.

http://www.garagejournal.com/forum/s...d.php?t=123447

Kevin

[KCarGuy]

I wish I would have kept the packaging, but here is a few Pics of it.
Inside it says; CT50K 1028

I like it because I need no Batteries, it has an "Off" switch and it can be set to 35 degrees for the winter to keep everything from freezing. Most dont go that low.

Also, Checking with my "Handy Dandy" Craftsman Infrared Thermometer...the temp of the Tubes blowing heat out of my 75K Beacon/Morris Heater reads 243 degrees!
(heats my 25 deep by 30 wide garage with 9 foot ceiling quickly)
The Reading on the Vent tube going out was 116 Degrees about 2 feet from the Heater.
Not bad.

[KCarGuy]

Lambo nut...Yep, that it the same one.
CT50K1028/E Honeywell
Thanks,

[brddog]

Originally Posted by KCarGuy

Lambo nut...Yep, that it the same one.
CT50K1028/E Honeywell
Thanks,

Thanks guys! I've been looking for something like this for some time

[dave67fd]

Yeah,
I saw this one as well but decided to get one that gave me the option of turning the fan on/off in the summer. I may decide to swap out to the 35 deg therm. if i don't find myself really using/needing the fan option.