Wood Furnance Add On Setup Help

[wildlandff18]

Morning all,

Just wanted to run this setup by the forum. I have experience with stand-alone wood furnaces, but never an add-on. My main is a forced air natural gas. I've done a bunch of research on this particular setup and found conflicting thoughts on whether or not it's correct. Here goes nothing.

1. The blower on the wood furnace is tripping the breaker. Looks like whoever installed the gas furnace wire it up - but left the romex disconnected in the j box. When I connected the wiring and turned the breaker back on it immediately popped. The blower itself spins freely. I only tripped the breaker once - then disconnected all the wiring again. Not sure if it's wired correctly at the blower. Checked all the wires to make sure it's not shorting out anywhere. Everything looks good in that regard. The blower itself is quite old (probably original).

2. Looking on this forum and others it seems like some folks don't use the blower on the furnace - just the fan on the HVAC system to pull the air through. So that's what I did. Got a fire going and kicked the fan to ON. Seems to work OK. I can't get the temp any higher than 67 but it stays constant.

3. I'm guessing there aren't any dampers installed in the duct work. If I turn the HVAC fan off warm air naturally flows out the HVAC return lines. Any concerns with this?

4. With the wood furnace going I am getting a faint smoke smell in the house. It's barely noticeably but it's still there.

Attached a few pictures of the setup. Do I need to get the blower on the wood furnace figured out to really make this work? If so I've seen quite a few people "boxing" in the fans so it's not pulling air directly out of the basement. Should I get some dampers installed before going any further? Just want to make sure this is all safe more than anything else. Thanks much!

 

[brenndatomu]

Job #1 is get that wood furnace checked out to see why there is a smoke smell coming into the house...and make sure your CO alarm is working!
Also, the stovepipe looks like galvanized...not allowed on a wood or coal furnace...it gives off toxic fumes when it gets real hot.

 

[wildlandff18]

Hey thanks for chiming in. CO alarms in all 3 bedrooms and 1 in the basement. All set there. Yeah it's galvanized - good to know it'll need to be swapped out.

Unsure of the age of the furnace but there aren't any gaskets on the doors. It looks like there never were any. Fiberglass rope looks doable. Also there's a return vent in the stack right next to the wood furnace door - so I'm guessing when I'm loading wood even a wisp of smoke is getting sucked into the system?

 

[brenndatomu]

The obvious older age of the furnace would make me want to have it looked over real well to make sure the firebox/heat exchanger is not cracked and/or rusted through...

 

[wildlandff18]

Ok that's a good call. I really only started messing with it due to the recent cold snap. Maybe I'll wait until spring to dig into it any further.

 

[Wood1Dennis]

Wildland....
I grew up in a house heated with a similar furnace. It looks a lot like the 1980 vintage Russel Stove in my parents house. It was still heating the house until about 8 years ago. Its no longer used, mostly because my mom can't do it any longer. I can possibly provide some insight.

Ours never had door gaskets from when it was new.

It has a similar blower that just pulled air from the basement. Later my dad connected it to the cold air return, but that was not original. The power to the blower plugged into a wall outlet. The power cord ran to the electrical box next to the smoke pipe on the back. In that box was a switch that was normally open, it would close when the furnace heated up to turn the fan on. Completely independent of the gas furnace. Maybe someone tried to get fancy on yours....

You can run the furnace without the fan, there should be two clamps holding a plate at the bottom up, can't tell for sure from your pictures. If you release those the plate will drop down so that heat will circulate up past the firebox by convection only. We used to do that in case of a power outage.

I can't tell from the pictures, but ours had a ash door with a round plate attached to a screw that was used to control the primary combustion air that came in through a grate on the floor of the firebox. There was a secondary air system that got it's air from an intake under that box looking thing on the back. It was really important to open the primary up and get it burning really good before closing it down or it would 'backfire' leading to some smoke smell in the house.

Ours had a heat exchanger. Smoke would exit in the middle of the firebox, above the secondaries, get channeled to the front, around both sides and combined in the back where the smoke pipe connected. The heat exchanger was a real pain to clean, but you will probably want to get a vacuum cleaner in there and clean it out if you are going to burn it.

It was a good unit in it's day, but the modern ones like my Caddy are far more efficient and burn a lot less wood!