Why so few wood burning furnaces with glass doors?

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Sorghum

Member
Apr 16, 2009
27
south central Minnesota
Why do most wood furnaces not have glass doors? I'm thinking of replacing a US Stove Hotblast (not because the door is steel).
I'm not talking wood stoves mind you, looks like there are many choices in that field.

There seem to be good add-on furnace, or LP or oil /wood combo furnaces out there. I think the Yukon Super Jack, Energy King, or Woodchuck all look fine. But I'd like to see whats going on inside!
The PSG Caddy's fit the bill with nice clear viewing possible. Why not the others? Personally I'd spend a bit more for glass.
 
The same reason my Propane Boiler does not have one.
 
Sorghum said:
Why do most wood furnaces not have glass doors? I'd like to see whats going on inside!
The PSG Caddy's fit the bill with nice clear viewing possible. Why not the others? Personally I'd spend a bit more for glass.

There are others, Here's one:
http://jaroby.com/index.php?page=fiche&no=27&cat=5

Not the prettiest, but it does have a glass door. EPA approved too.
 
I get the impression that although the principle of burning wood for heat is the "same" on some level, the "furnaces" are designed to be more self-sustaining and not in need of as much direct attention. Fair statement? That's been my impression anyway.

-Soupy1957
 
My guess is that since furnaces/boilers transfer heta to a medium to be distributed throughout a house. A glass door would probably radiate a much larger percentage of the heat in the space where the appliance is, which is probably what most people are not looking for.
 
I like soupys answer. usually a furnace is in the garage or utility area where there is not going to be people looking at it anyhow. If you want to see open the door, then shut it and leave.
 
I have a Super Jack located in the basement. I really wanted a glass door and when learning how to run the furnace I wish I had one. Now after almost and entire season of 24/7 burning, I have my routine down and do not need to see the fire. When I want my fire fix, I will sit in front of it with the door open for a few minutes.

The furnace was bought to do one thing and that is throw alot of heat to distant places in the house while reducing our propane usage. It does exactly that, as we have saved about $3000 this season alone. With that said, I am currently shopping woodstoves for shoulder season and the ability to see the fire.
 
I'm sure now that the Caddy has really taken a lot of market attention you'll see others start to do it. Same thing happened 30 years ago or so. Some fool put a glass door in a wood stove..why? Well, then they all started doing it. Then someone developed air wash..you'll see it more and more. If you cant wait, just buy a Caddy, know you bought an excellent furnace and get that little tax credit that is still floating around.
 
There is a difference between: Lights dimmed in the parlor ---- a flickering flame in the hearth ---- and wine by candlelight.

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Lights out in the furnace room ---- fire roaring in the furnace ---- and beer by flashlight.
 
It is funny that our old washer and dryer did not have a window and they cost $1000 for the pair. The new washer/dryer have windows and cost $1000 a piece.
 
I love the view of the fire from our Caddy. Even though i'm not down there all the time. I have no heat registers in our basement, so the heat from our furnace that radiates through the glass heats our 1,200 sq.ft dungeon for a basement. I don't think it drops below 60 and the side with the furnace stays around 65 or so. Then the furnace itself from the firebox and heat exchanger heats the other 2400 sq. ft above it on both floors. Theres a napoelon furnace now on the market that has a glass door, or an optional insulated door. Also one of the benefits of having a EPA furnace, we can heat through the shoulder seasons with no issues with creosote. A small hot fire will burn cleanly and the coal bed will produce heat for a while. I could picture a Caddy in a new home in a finished basement. You could view the fire, feel the radiant heat and know its heating the whole home. After having one for a couple years, I wouldn't install it outside the home.
 
my englander addon has a nice big viewing window ,i couldnt imagine not having one ,its so convenient to see whats going and being able to monitor and adjust the intake and damper controls without messing with opening up the door,we can see it from our finished office downstairs ,it really adds ambiance to the room and my lab enjoys the show as well
 
Thanks for the input. I'm not looking for ambiance because this is in the basement of a 135 year old brick house. There's not living space down there.
I'd like to see what's going on. How the fire reacts to changes in controls like damper, ash door spin knob, baro damper and the like. Watch flue temps change.
And opening the door changes the operating characteristics. I guess that I'm not happy with the current set up and pretty much want to start over. Getting something with secondary combustion efficiency, with the associated light show seems like a no-brainer. (And have a beer or two while I school myself.) Like JDC said I'd want it to learn how it runs, then after a while it would probably be no big deal.
 
Simple answer.....because most would be coated with ash, soot and creosote within days rendering them useless.
 
heaterman said:
Simple answer.....because most would be coated with ash, soot and creosote within days rendering them useless.
Yeah never thought of that. Good point. It takes a properly designed unit to keep the glass clean.
 
I took the sheet metal cover off the door so that I could see thru the sliding air control on the door. I usually run it with just a very slight crack, less than 1/8". On really cold, windy days it might be open as much as 1/4". Would I like a glass I could see thru? You bet. Not for ambiance, just to see how the fire is burning. Opening the door and taking a quick peek doesn't really work for my setup.

Hopefully, this is my last winter burning it full time. If I don't move, I'll have a stove or insert upstairs. With a window. I'll keep the furnace for a while, to see if the stove can keep up on the cold days. I'm tired of running to the basement all the time, and it will be easier for my wife for the two days a week I'm out of town.
 
One of these is on my wish list, my door has to be hand cranked open. weights about a 1000 lbs I don't have the issue of opening the door to often but it would be nice to have a better view of the burn.


The Saf-T-Eye observations ports, when placed in a suitable position on the furnace, oven, or boiler wall, enable the operator to safely and clearly inspect the interior. Adjustments can be made under actual operating conditions without air infiltration or flame sting-out. Three types of glass are available for a variety of viewing options, such as borosilicate, cobalt blue, and quartz glass. The glass is protected by a stainless steel screen and shutter, which closes automatically when the handle is released. Wing nuts allow the glass to be easily removed for cleaning or replacement.
 
i just got one of them englander 3500's tonight man is it big! cant wait to hook it up, how you guys hookign them up to your ducktwork of your existing forced air furnaces? is there some tricks?
 
We make the Caddy. Couple reasons why other may not put glass 1) cost, it cost more in material and manufacturing to put glass in 2) Once you put glass in you might as well design an airwash otherwise it's a waste of time 3) If you have an airwash it means you likely have an EPA furnace and there's few on the market yet.

As a side note, most Caddy users will tell you they love to be able to see what's going on inside. Dont have to open the door to see if it needs more wood. As someone else said, eventually they will all have it.
 
I hear you Sorghum. I wish I had the choice of a glass door as well. I did not see any wood burning boilers with a glass door. I liked to watch the fire in the P.E. Super 27 wood stove, especially when I am trying to unwind with a beer, or 5, once every couple of weeks. Now, when I get my wood burning gasser boiler hooked up the wood stove will be just back up and no more viewing the fire. Can I leave the bottom door on my Wood Gun open and watch that when it is in gassification mode? :cheese:
 
FyreBug said:
We make the Caddy. Couple reasons why other may not put glass 1) cost, it cost more in material and manufacturing to put glass in 2) Once you put glass in you might as well design an airwash otherwise it's a waste of time 3) If you have an airwash it means you likely have an EPA furnace and there's few on the market yet.

As a side note, most Caddy users will tell you they love to be able to see what's going on inside. Dont have to open the door to see if it needs more wood. As someone else said, eventually they will all have it.

You dont make the Caddy! Elves make Caddys. Someone had to be the innovators. By the time the world catches up with PSG, PSG will be selling Caddy Wood Boilers.

You heard it here first!
 
Franks said:
FyreBug said:
We make the Caddy. Couple reasons why other may not put glass 1) cost, it cost more in material and manufacturing to put glass in 2) Once you put glass in you might as well design an airwash otherwise it's a waste of time 3) If you have an airwash it means you likely have an EPA furnace and there's few on the market yet.

As a side note, most Caddy users will tell you they love to be able to see what's going on inside. Dont have to open the door to see if it needs more wood. As someone else said, eventually they will all have it.

You dont make the Caddy! Elves make Caddys. Someone had to be the innovators. By the time the world catches up with PSG, PSG will be selling Caddy Wood Boilers.

You heard it here first!

Hush! It's supposed to be a secret!
 
We incorporated a glass viewing pane in the high-efficiency ENERGY KING 385EK wood furnace (I've attached a photo). It actually helps to maintain the higher efficiency because you don't have to open the door to monitor the fire (opening the door changes the combustion air balance, so you don't really get an accurate picture when the door is open anyway).

We solved the soot/creosote thing by just building in an airwash, like in a small woodstove. Works like charm :) Granted, it's not a large window, like on a fireplace, but it's big enough to check on the fire when you need to, and to enjoy the flames when you want to.

We actually get a lot of requests for the new door from owners of our older model furnaces and boilers. It's too bad that it's a different shape, because I think there are quite a few homeowners that would like to have glass on their wood furnace or wood boiler door.
 

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Sorghum said:
Why do most wood furnaces not have glass doors? I'm thinking of replacing a US Stove Hotblast (not because the door is steel).
I'm not talking wood stoves mind you, looks like there are many choices in that field.

There seem to be good add-on furnace, or LP or oil /wood combo furnaces out there. I think the Yukon Super Jack, Energy King, or Woodchuck all look fine. But I'd like to see whats going on inside!
The PSG Caddy's fit the bill with nice clear viewing possible. Why not the others? Personally I'd spend a bit more for glass.


Dont sure I want anyone to see that big square box let alone a window to view it.... :cheese:
 
Fred61 said:
There is a difference between: Lights dimmed in the parlor ---- a flickering flame in the hearth ---- and wine by candlelight.

-------------------------------------------------------verses ---------------------------------------------------------------------------

Lights out in the furnace room ---- fire roaring in the furnace ---- and beer by flashlight.

I've been known to disappear into the basement with a beer and a few splits. Until I hear "What the heck are you doing down there!?" from the top of the steps ;)

greythorn3 said:
i just got one of them englander 3500's tonight man is it big! cant wait to hook it up, how you guys hookign them up to your ducktwork of your existing forced air furnaces? is there some tricks?

Did you buy it new? If so the manual is pretty self explanatory. If not, you can download it in PDF online. I detailed my Englander install start to finish here:

https://www.hearth.com/econtent/index.php/forums/viewthread/41418/
 
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