Harman Stove Company SF1500A manual Duct Work and Operating Instructions

Duct Work and Operating Instructions

Duct Work.

This figure shows a typical duct system layout. Be sure the entire system is properly sized to provide the correct

static pressure for optimum blower Return AirSupply Trunk performance. Have any new duct system

designed by a HVAC professional.

Operating Instructions

Plenum

Adjusting Automatic Draft Control - In order for your new furnace to function, the controls must be properly adjusted. The heat output is regulated by the automatic draft control, on the bottom

door of the furnace. Refer to the illustrations at right; The electric draft motor (A) opens and closes the flapper door (B). The flapper door opens to feed more air to the fire and closes to reduce the air to the fire. The maximum air flow can be adjusted by turning the adjuster bolt (C) counter-clockwise for more air and clockwise for less air. NOTE: To preserve motor life, all adjustments of this bolt should be done while the flapper door is in the closed position. The idle adjuster (D) controls the minimum amount of air that enters the firebox when the flapper door is closed. Adjustment is made by turning the adjuster vertical for zero air, or horizontal for maximum idle air. It is best to start at a medium setting as shown at right.

Adjusting the fan control- Shut off the power at the circuit breaker before removing Figure 6 the fan control cover. Make sure the copper jumper (circled below) is removed before

using the furnace. Note the three pointers on the dial. The one on the right is the high limit adjustment. Pre-set at 200 degrees, it’s function is to close the automatic draft control flapper door if the temperature in the plenum reaches 200 degrees. Do not change this

setting. The center pointer adjusts the temperature at which the blower starts. A good initial setting for this is 150 degrees. The pointer on the left is to adjust the temperature at which the blower stops. A good initial setting for this pointer is 100 to 110 degrees. If it is set too low, the air will feel cool coming out of the registers at the end of the blower cycle.

Thermostat- Set the thermostat to the desired temperature. When more heat is needed, the thermostat opens the automatic draft control flapper door. This allows air into the firebox, which raises the output of the fire. When the temperature in the plenum reaches the set temperature of the center pointer on the fan control, the blower will begin blowing heated air through the ductwork. When the thermostat reaches it’s setpoint, the automatic draft

Figure 7 control closes the flapper door, thus, reducing the output of the fire. As the temperature in the plenum drops to the set point of the left pointer on the fan control, the blower will stop. A solid fuel fire cannot cease output immediately, therefore, your room temperature may exceed the thermostat setting at times. You also may notice times that the blower runs for a short period even though the draft control is closed. Again, you can’t just stop a wood or coal fire instantly, and temperature may build enough to run the blower. This is normal and will be noticed more with coal than with wood.

Figure 5

ZERO

MED

MAX

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