Other Unit Adjustments
Primary Limit.
The primary limit is located on the heating compartment vestibule panel. This limit is factory set and requires no ad justment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of the burner box.
Pressure Switch
The pressure switch is located in the heating compartment on the cold end header box. This switch checks for proper combustion air inducer operation before allowing ignition trial. The switch is
Temperature Rise
Place the unit into operation with a
Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace operating). Correct voltage is 120VAC + 10%
3 - Check
Unit Nameplate__________Actual__________
Exhaust and Air Intake Pipe
1 - Check exhaust and air intake connections for tightness and to make sure there is no blockage.
2 - Is pressure switch closed? Obstructed exhaust pipe will cause unit to shut off at pressure switch. Check ter mination for blockages.
3 - Obstructed pipe or termination may cause rollout switches to open. Reset manual flame rollout switches on burner box assembly if necessary.
Heating Sequence of Operation
Electronic Ignition
The
NOTE - The ignition control thermostat selection DIP switch is
Applications Using a Two-Stage Thermostat
A - Heating Sequence
Selection DIP Switch 1 OFF in “Two-Stage” Position
(Factory Setting)
1 - On a call for heat, thermostat
2 - Once the control receives a signal that the low pres sure switch has closed, the combustion air inducer be gins a
NOTE - If the low fire pressure switch does not close the combustion air inducer will switch to high fire. After a 15 second
3 - After the
4 - After the
5 - If
6 - At the end of the recognition delay, the integrated con trol energizes the combustion air inducer at high speed. The control also checks the high fire (second stage) pressure switch to make sure it is closed. The high fire (second stage) gas valve is energized and the indoor blower motor is energized for operation at the high fire heating speed.
7 - When the demand for high fire (second stage) heat is satisfied, the combustion air inducer is switched to the
8 - When the thermostat demand for
9 - When the combustion air
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