Too Much Moisture in Your Firebox Will Damage Your Outdoor Boiler - How to Achieve a DRY BURN

 Hey Patriot - You got this, right? Your boiler runs great and saves you a ton of cash every year. This is what we hear people saying:

“I love it! It runs great!”
“I have never had a problem with it!”
“This thing was the best investment I have ever made!
Until it doesn’t run great. Then it wasn’t the best investment you ever made.
Don’t assume that just because it runs great, that it will keep running great without you taking care of it. Kinda like the guy who thinks his car is running great without oil…until it doesn’t!
So since the EPA banned outdoor boilers, you can’t replace your boiler once it reaches its end of life. That’s why we want to help you make your boiler last forever!
Yes this means you have to do your normal maintenance, ash management, use water treatment, get the water tested and all that important stuff…
But the thing ALL outdoor boiler owners – especially those whose furnaces start to have problems – wish they had started doing SOONER, is what we call the DRY BURN.
What is the DRY BURN?
All wood contains lots of moisture. Even the most seasoned hardwood contains 20% moisture. That is a LOT of water.  When the wood burns, that water has to burn off; it evaporates into steam and mostly leaves the boiler out the stack.

But some of that moisture condenses on the inside of your boiler. This is bad.

Remember that when water touches steel, there is corrosion. When moisture condenses on steel surfaces and lingers there, you have LOTS of corrosion.

But if you have a DRY BURN every day, you prevent that corrosion! 

How do you get a DRY BURN?
As wood burns, the moisture is slowly burned out of the wood.  Unfortunately, that moisture is coming out of the wood for most of the burn cycle – it is only at the very END of the burn cycle when the wood is just dry hot coals that all the moisture is out of the wood. This is the DRY BURN state. If you burn your boiler in the DRY BURN state for several hours, you get a DRY BURN!

But many outdoor boiler owners never allow their boilers to reach this state. The load up their boiler in the morning with a huge load of wood, and by the end of the day, the wood is only half-burned. This wood has NEVER reached a DRY BURN state, and is still giving the inside of your boiler a moisture bath. Then they “TOP OFF” their firebox burn chamber with more moisture-filled wood, adding even more moisture to the process.  This boiler never experiences DRY BURN.

Don’t be the guy who says this: “This doesn’t apply to me. I only use SEASONED wood! My wood was cut two years ago!”  THAT DOESN’T MATTER! Even the most seasoned hardwood contains about 20% moisture. That is a lot of moisture, and you gotta deal with it, before it deals with you.

Unfortunately, boilers that don’t get a DRY BURN every day, will begin to experience damaging corrosion. The parts of the boiler that are cooler (such as the perimeter of the door) start to show corrosion damage. The ASH will absorb this moisture and if not removed often, will form an acid paste that eats through steel. Steel in the corners can begin to show pitting damage that, if left unchecked, will lead to a leak in your steel.

One other problem you may experience is a tremendous amount of moisture will drip off your chimney cap and create rust corrosion on your roof. This will require that you sand your roof every year, and repaint it. If not repainted annually, then over time, this corrosion can eat holes through the roof!
The solution is simple!  Only load into your firebox the amount of wood needed to get you to your next fill. You want your wood to burn down completely to coals and burn in that DRY BURN state for the last few hours of every wood load. This will dry out all the components that may have become moist from condensation. This will protect your boiler – and your INVESTMENT! 

Use this DRY BURN technique to keep your boiler healthy for decades to come!


For more information, click HERE to read our newsletter on this topic.