The Chimney Sweep Online Fireplace, Woodstove, Gas Stove and Barbecue Shop
Q: We just bought a new, EPA approved woodstove from our local dealer, and while reading the owner's manual, we noticed a precaution against 'overfiring'. Our dealer says he has no idea what this might mean. Do you suppose the term 'overfire' means to get the stove too hot? How can that be? Doesn't a woodstove have to get hot in order to heat the house? If the stove can be damaged by over-heating, please give us some input from your experience as to what are the indicators it is getting too hot, and what sort of damage can result. Finally, is overfiring an issue with the woodstoves you sell? We hate to think we bought a woodstove that must be babied for fear it might self-destruct!
Ever seen a Blacksmith's forge in action? The concept is simple: hit a big, hot fire with enough oxygen and you can melt iron and steel like butter. Since all woodstoves have iron or steel components, they can all be damaged if simultaneously given too much fuel and too much air (the situation referred to in your manual as overfiring).
This doesn't mean you have to 'baby' your stove:
Here's a pretty good analogy:
Driving a wood stove presents a similar situation:
Be mindful of the octane level of your fuel:
Put a "tachometer" on your wood stove:
Plan your trips in advance:
With practice, proper driving habits become automatic:
Q: I read your article about overfiring a wood stove, and it seems to make perfect sense, except for one factor you seem to have conveniently overlooked: when I turn my stove down so it's burning in the 500 - 650° "cruise" range you recommend, it won't heat my house! I'm interested to hear what your comment might be about that!
- Cold in Ontario
Actually, this one's easy: if your stove isn't capable of maintaining a comfortable room temperature while operating in the cruise zone, you need a larger stove, a second stove, or a better-insulated house.
Q: My dad had several wood stoves while I was growing up, and he operated them all by the same rule: "Wait til she starts to glow, then turn 'er down to low." Seems to me dad's little rhyme conveys the same information as your several-paragraph article on Over-Firing, eh?
- Simon Berger
Almost. By the time those stoves began to glow, they had reached at least 900°F. Which is deep in overfire country, especially when you consider the total time spent in the red zone during the journey there and back. If ol' Dad made it a regular habit to wait until he saw his stoves glow before adjusting the draft control, he was subjecting the metal to systematic torture. Might explain why the family went through several stoves in such a short period of time, eh?
Q: About your comment that 900° is "deep in overfire country", it has been reported on an online wood heat forum that at least one manufacturer has OK'd that temperature (for their brand, anyway). What say you about that?
- No Name, Please
A mixture of misunderstanding and sloppy reporting, I'd say. It simply defies the imagination that anyone qualified to be a spokesperson for any wood stove manufacturer would OK stoking the stove until it glows (which is what happens at 900 degrees) as a general practice. I happen to be familiar with the post you mention, and the fact is, the manufacturer in question actually states in their manuals that if any part of your stove is glowing, you are overfiring.
Most likely, the real scenario was something like this:
Frantic Stove Owner: "I got distracted and left the room while I was kindling a fresh load with the draft control wide open, and by the time I came to my senses and ran back in, my stovetop thermometer had reached 900 Degrees! Did I destroy my new Reactor 2000 wood stove?"
Nuclear Stove Co. Customer Service Rep: "No need to panic. We build extremely stout stoves here at Nuclear, and one short trip to 900° most likely did your Reactor 2000 no harm."
No-Longer-Frantic Stove Owner's Forum Post: "Hey, I called Nuclear Stove Company, and they said running the Reactor 2000 at 900° is no big deal."
Inevitable Result: An unusually large percentage of forum members subsequently complain of heat-damaged stoves.
Miscellaneous Comments, heavily condensed from the original E-mails:
Regardless the gear, if
you're redlining, taking your foot off the gas (reducing airflow by closing down
the damper) always works.
The Honest Abe Analogy:
You should replace your tires if you can see Lincoln's head when you insert a
penny into the treads, and you should replace your door gasket when the latched
door won't hold a $5.00 bill!
Household garbage in a
wood stove is like leaded gas in a car: don't burn it.
Here's one for your
auto-stove comparison page, unless, as I suspect, you write all the letters
Roland, as evidenced by your contribution, the letters we publish are from real visitors to our website. Now, go tell Warren Zevon you actually exist.
The Chimney Sweep, Inc.