Wood stoves - Q&A FAQ

Not sure about larger units....
I have a military tent heater unit that came with all kinds of stuff...
It can burn wood, coal or liquid fuels.
Only The clinker and shaker grate for coal is removed, and the large grate left in the base for wood burning.
I have 2 cast iron stoves that will burn wood and coal and the only difference is, I just take out the shaker assembly and put the wood in.

 

It's rare that I can't answer a fireplace or stove question, but we have no coal burning in Colorado so I have no experience with it. There is no installed base of coal stoves here, either. Nothing.

Fischers were great stoves back in the day. Stout as hell, and well made. They, along with a lot of other companies, didn't make it through the EPA imposition of emission standards in the 80's.

Modern EPA Phase II stoves admit about 20% of the combustion air right at the floor of the stove. The remainder comes in through the secondary burn tubes at the top of the firebox and right at the top of the glass door as an airwash that helps keep the glass clean. The additional oxygen coming in through the tubes reignites superheated smoke is to burn the particulates out of it. That's how they burn clean enough to be approved, and it yields phenomenal efficiency.

Even low-sulphur coal produces sulphuric acid when it burns, which is really hard on chimney systems. If the chimney is compromised, the higher flue gas temps of a wood fire could have unpleasant results. That rig is at least 25 years old, and it should be inspected by someone competent - meaning not your typical chimney sweep - before you use it. If you'll post pictures I can probably walk you through an inspection.

You should be able to close that shaker grate, if it's still in good shape. Light the fire directly on the floor of the stove. For best results, leave at least 1/2 inch of ash on the floor of the stove when you clean it out.

I'm really busy right now, so if you post pics of have any other questions, please PM me so you don't have to wait a few days for me to respond.

 

There is a company in Oregon called Fisher’s Hearth & Home, they were a Fisher dealer until the company went poof. They may have some old Coal Bear manuals, or even someone who knows about Coal Bears (Since Fisher was in business until as late as the mid 80's). Apparently there are "Fisher" stoves still made in NZ, I went to their corporate site, simple, nothing fancy. As to your question, it is indeed top air supply for wood, bottom for coal including charcoal, that is why a forge has forced air vents on the bottom, beneath the fuel supply, same thing for your BBQ).

My dad's ranch had Franklin Air Tight stoves, as did my grandparents farm. They swore by them, and the air feed was from the sides and top. The bottom was an ash drawer that, if not sealed properly would cause excessive overheat, which in turn could lead to a flue fire. IF the metal of the case or flue starts to glow, the fire is too hot, shut down the dampers and close off air supply until the glow subsides. The upside to coal is twofold: A) anthracite burns cleaner (it has a very high carbon content), and B) it burns longer. It was not unusual for a good coal fire to burn 16 hours without adding fuel. The down side is that all coal has sulfur in it and when it burns, it makes sulfuric acid (this is where acid rain comes from, dontcha know?), which eats metal like candy, so be aware the flue pipe may have thin spots or even be compromised due to the corrosive nature of the smoke.

 

OK - that looks like the body of a standard Fischer stove with an additional bottom unit added for the coal grate/ash collector/bottom air intakes.

If the house is only 20 years old, then the stove was already well used when it was installed. I see a lot of rust on the connector pipe and would replace it immediately. You might look into rigid stainless chimney liner, which can be used as connector pipe but is corrosion and acid resistant. That, or use double wall connector, which has a stainless inner wall and will also help keep flue temps up.

I see rust on the stove too (do yo live in a humid area?) but that is more of a cosmetic issue. (As I mentioned, Fischers are stout - the ones I've seen were made of 1/4" and 5/16" steel plate.)

If you're satisfied as to the condition of the chimney and have inspected the body of the stove for cracking welds, then try it out.

But ABSOLUTELY put in CO detector and smoke detectors before you light it up.

 

That's called overfiring, and with modern stoves it most often happens if you forget to close the door after establishing a good draft. The same thing will happen if you have worn out seals or large cracks in the body of the stove.

And, if overfiring leads to a chimney fire, well, that's creosote burning. The chimney wasn't clean enough.

This is an argument for installing an EPA Phase II stove. (These were only made after 1990, and are best purchased new.) One of the benefits is much cleaner burning, particularly at low air settings where most of the creosote is deposited in the flue. But there are more reasons to go this way: the much higher efficiency means you need less wood per season. That means less cutting, hauling, splitting, stacking, storage space, stoking, and ash cleanout.

I find people use 1/4 to 1/3 less wood when they switch to a modern stove. That's significant in peacetime, but it could be critical in a survival situation, when you'll have plenty else to do and never enough time in a day.

 

Just glanced at your pics again, and that wood is stored too close to the side of the stove. If that's still there, you need to remove it. The default clearance between a stove and the nearest combustibles is 36" unless you add specific heat shielding or have manufacturer's data allowing less.

 

Glad to help. I'm no longer in the business, but the handle seems to have stuck to me, along with the knowledge. At one point I was certified as an installer and as an inspector, but I allowed those certifications to expire because I just don't have the money or the patience to travel to trade shows or take more classes, which are the only sources of continuing ed credits. The inspection end of it was fascinating, as you get to solve odd problems and if you're really good, do post-fire forensics and expert witness work. What little expert witness stuff I did was fun, but before you get much of that work you have to get established in your market by doing residential resale inspections. Unfortunately, that work more or less died when the housing bubble burst shortly after I earned the designation.

I get referrals and repeats now and then, and can still get my hands on many brands of stoves along with pipe and parts at wholesale, so I'm not completely out of the business. Biggest thing I shed was the overhead, thank God.

So, ask away....

 

Buy the replacement connector pipe now. I think chimney pipe will disappear quickly when TSHTF. Heck - as it is, there's an annual chimney pipe shortage at the beginning of every burn season (right around Labor day) because the distributors all prefer to lose a few sales rather than tie up capital a week too soon. The don't run out of everything, but they are all out of the same things at the same time, usually including some key support or bracket that you MUST have to build a chimney.

One cool thing about the fireplace business is that your inventory makes for great barter stock. I've always gone long on pipe, chimney brushes and rods! (And this has been proven in real life. Right after Katrina, when fuel prices spiked, I did a land office business selling pipe to people who had an old stove lying around that they wanted to install. For a week or so, when everyone else was out of some parts, I was the only game in town. It's fun when you can say "yes, I have that part but I'll only sell it with a complete chimney system." I did close to $10K in chimney when everyone else was paralyzed.)

Which brings me to another interesting fact about this industry: it is far too small to cope with unexpected demand. After Katrina, the distribution pipeline quickly emptied out and the whole industry was 8 to 20 weeks behind (depending on brand and model) on wood and pellet stove orders. (Of course, the reps were telling us "2 or 3 more weeks" all winter long!) That was a tough season.

You can add wood stoves and chimney pipe to the list of things that will disappear quickly in a panic, for sure. Been there, have the scars.

 

I have hard copies of both the pre-1980 and the post-1980 Fischer manuals in my files. I checked them before my first post here. They do not address the Coal Bear. Furthermore, a number of the installation practices shown are outdated. A few are, frankly, unsafe.

And beware Hearth.com. There is a lot of good information there, but they have a bizarre animosity toward people like me who are real sticklers for safety. They accept paid advertising from the industry, and refuse to advocate any safety practice that might cost an advertiser a sale. Years ago, I was banned from their forums for insisting that a wood burning fireplace insert should only be installed in a masonry fireplace, and stating why. (What I stated there has since become part of the curriculum of the National Fireplace Institute's certified installer program.) Didn't help that I'm a real conservative, either, since the site's owner (one Craig Issod) is vile character somewhat to the left of Obama. (And I can back that up.)