Wood Boiler Log Length

by Mark


What is the best log length to burn in an outdoor wood boiler?

Presently, I'm cutting my wood at 22 inches. Thanks


There's a couple of different theories when considering the best log length to burn in an outdoor wood boiler.

Depending on the specific model, some outdoor stoves have fireboxes that are nearly 4 feet deep allowing you to burn some really big logs.

There's a lot of people who cut their wood "as big as they can lift" meaning they make the logs as long as possible while still being able to throw them in the stove.

While this sounds like a good way to reduce the processing time it actually has several disadvantages. First, trying to toss huge logs into the firebox can easily hurt your wrist, elbow or shoulder......it's just not worth it.

I remember the first year we used our wood boiler I tried to toss a really big chunk of wood into the stove and it hurt my wrist. The injury plagued me the entire year. I learned my lesson the hard way.

Second, I've found that long pieces of firewood make it difficult to regulate how much wood you add to the fire. Since an outdoor wood boiler can quickly accumulate a lot of coals in the bottom, it's important to add the "right amount of wood."

Too much wood and you're left with a huge pile of coals that just takes up room in your firebox and you eventually have to scoop them out. Too little wood and you don't have enough coals to light your fire the next morning.

Although it doesn't take long to get the hang of adding the right amount of wood to your stove, having a standard size log makes regulating the wood a lot easier.

If you're currently cutting your logs 22 inches in length I think that's about the perfect size. I've experimented with several different lengths and 22 inches is roughly what I prefer.

At 22 inches the logs are still easy to handle whether you add them whole or place them on a splitter. Plus, you're still cutting them long enough to reduce the amount of cuts you have to make during the season.

To increase efficiency, the way you load the wood into the boiler also makes a difference. I've found that stacking the wood in a single row pyramid seems to work the best as apposed to just randomly tossing wood into the firebox.

The pyramid allows you to judge a constant amount of wood day after day plus it seems to burn slower and not waste BTU's.

Overall, I think 22 inch logs for a wood boiler is a great choice and unless you're experiencing a problem I wouldn't change it.

Firewood For Life

Comments for Wood Boiler Log Length

Average Rating starstarstarstarstar

Click here to add your own comments

Jan 13, 2015
Log length
by: Joe

I agree that 22" may be an ideal size but in some boilers 22" is a bit too small. I think in the larger boilers 27-30" is perfect.

In my case the firebox is 60" deep. I cut my pieces 27-30" leaving 8" from the door and ample space in the rear of the boiler. It seems to be much more efficient.

Click here to add your own comments

Return to Ask A Question.