Operation, Automatic Draft Control

Operation

Automatic Draft Control

The heat output is regulated by the automatic draft control on the bottom door. The electric motor (A) opens and closes the flapper door (B). Opening and closing the flapper door regulates the air flow into the firebox.

The maximum air flow can be adjusted by turning the adjusting bolt (C). Turn counter-clockwise for more air, and clockwise for less air. Adjust this bolt only while the flapper door is in the closed position. Otherwise, motor damage could occur.

The idle air adjuster (D) controls the minimum amount of air that enters the firebox. Adjustment is made by turning the adjuster vertical for zero idle air, or horizontal for maximum idle air. It is best to start out with a medium setting as shown in Figure 9.

FIG.8

FIG.9

Starting a Wood Fire

Make sure the boiler and all piping is full of water and that all air has been purged from the system.

Never start a fire without water in the system. An explosion will occur.

Turn on electrical power to the boiler. This should cause the automatic draft control to open.

Open the ash pan door to allow free air movement. With the firebox door open, crumble approximately 8 sheets of newspaper and place on the grates. Lay some small kindling on top of the newspaper. Be sure this kindling is dry and no more than 3/4 in. in diameter. Layer the kindling in a criss-cross type pattern, to allow maximum air flow. Next lay some larger pieces of wood on top of the kindling (approximately 2 in. diameter). Using a match or lighter, light the paper just inside the door. Close and latch the firebox door and allow the fire to burn a few minutes. After about five minutes, close the ash pan door and re-open the firebox door an inch or two, to allow the smoke to clear. Add 4 or 5 larger logs (about 4 in. diameter) to the well established fire and close the firebox door. Leave the ash pan door open for about five minutes only. Now open the firebox door using the same method as before, always closing the ash pan door before opening the firebox door. Now you can load the firebox to the desired level. You may load wood to the top of the firebox. Close and latch the door. The ash pan door may again be opened to speed the ignition process.

Do not leave the boiler unattended with any door open.

After the wood is burning well, close the ash pan door. The automatic draft control will now regulate the fire, based on temperature demand.

The idle air adjuster must be tuned to where the fire doesn’t go out during long periods with no demand. Experience will dictate the best setting for your installation. Normally, the two manual draft controls on the firebox door are kept closed while burning wood.