Outdoor Furnace: Protect Your Door From Warp Damage!

Outdoor Furnace: Protect Your Door From Warp Damage!

Protect Your Door From Warp Damage! How Your Fire Can Destroy Your Firebox Door!

Many outdoor wood boilers have a blower fan that feeds air to the fire in the door. This fan has a damper that opens when the fan comes on and closes when the fan is off which prevents air from fueling the fire when in the idle mode.

Can the fire on the inside of the outdoor wood furnace damage the door?



When your wood and coals are too close to the door on the inside.


Because when the wood and coals (and ash if you haven’t been paying attention and haven’t been removing the ash properly…HINT, HINT!) are too close to the inside of the front door, then the air that is being fed to the outdoor wood burner will produce super hot flames that can be REDIRECTED BACK AT THE DOOR.

These super hot flames can also WARP your door frame, such that the door will no longer fit tightly.

If you have noticed any warping in your door, in your door frame, or even if you have seen any of the paint on your door start to peel, perhaps you have had a fire too close to the inside of the door.


Keep all wood, coals, and ash at least eight inches (8”) from the inside of the door frame. NOT 8” FROM THE INSIDE OF THE DOOR, but rather 8” from the inside of the DOOR FRAME.

In other words, if you put your hand on the door frame and move it forward, you will reach a point where your hand drops off the door frame into the inside of the firebox – THAT is the inside of the door frame of your outdoor boiler. Keep your wood, coals, and ash AWAY from this area, and only load wood at least 8-12 inches away from this drop-off.

Keeping the hot wood, coals, and ash clear of this area, and only building your fire further inside the firebox will protect your firebox door from damage, and enable you to continue saving money for decades to come!

For more outdoor wood boiler parts, visit our online store OutdoorBoiler.com!

Troubleshooting FAQs:

  • Why am I not getting hot water?

Check that the hot water system is connected properly. Check if the heat exchanger is partially or totally clogged.

  • I can't find a leak in my furnace. Why am I losing water?

The furnaces use a non-pressurized system, this means that the system is exposed to the air. Since the water in the system can and will be warmer than the air, there will be evaporation of the water in the system. The water must be checked and adjusted at least once a month, sometimes more.

  • What are the Common Insulated Pipes Problems

Pex has its problems, however, and those should be understood when considering the piping.

Click HERE for WORLD'S BEST INSULATED PEX: HEAT MIZERT Underground Insulated Pex. Other outdoor wood furnace parts are available too!

  • My furnace stopped running what should I do?

Check if there is there power to the furnace? Does the light work? Check the high limit switch?

Is the blower and or solenoid working? Are the wires in good condition?