5.Open Limit Control (Primary or Auxiliary)
An open limit control can be caused by a low condi- tioned air flow due to dirty filter or resistance in duct work, a faulty blower, a blower speed set too low, or a faulty limit.
When the limit control opens, the induced draft and air circulation blowers are turned on. The induced draft blower will remain on for the first fifteen seconds of this period. The air circulation blower will remain on until the limit control is closed. The diagnostic light code for this is four short flashes followed by a pause.
6.Open Rollout Control
An open rollout control is can be caused by insufficient combustion air, a restricted flue passage, or a re- stricted heat exchanger.
The opening of the rollout control signals the air circu- lation blower and the induced draft blower to turn on. The air circulation blower will remain on until the limit is manually reset. The induced draft blower will remain on for the first fifteen seconds of this period. The diagnostic light code for this is five short flashes followed by a pause.
7.Flame Sensed with No Call for Heat
If the control senses a flame when the gas valve is de- energized, it will run the air circulation blower and the induced draft blower continuously. The diagnostic light code for this is continuous light flashing. Probable cause is miswiring.
OPERATING INSTRUCTIONS
1.Close the manual gas valve external to the furnace.
2.Turn off the electrical power supply to the furnace.
3.Set room thermostat to lowest possible setting.
4.Remove the door on the front of the furnace.
Note: This furnace is equipped with an ignition device to automatically light the burners. Do not try to light burners by hand.
5.Honeywell Model VR8205, or White Rodgers Model 36E36, or Robertshaw Model 7222: Turn the gas
control knob clockwise 
to the OFF position. Note: The knob should turn easily. Do not use exces- sive force.
White Rodgers Model 36E22: Push the switch to the OFF position.
6.Wait five minutes to clear out any gas. Then smell for gas, including near the floor.
7.If gas can be smelled following the five minute waiting period in Step 6, immediately follow the instructions on Page 2 of this manual. If you do not smell gas after five minutes:
Honeywell Model VR8205, or White Rodgers Model 36E36, or Robertshaw Model 7222: Turn the gas
control knob counterclockwise 
to the ON posi- tion. The knob should turn easily. Do not use exces- sive force.
White Rodgers Model 36E22: Push the switch to the ON position.
8.Replace the door on the front of the furnace.
9.Open the manual gas valve external to the furnace.
10. Turn on the electrical power supply to the furnace.
11. Set the room thermostat to the desired temperature.
NOTE: There is an approximate 20 second delay between thermostat energizing and burner firing.
Gas Valves
Figure 36
Honeywell Model
Figure 37
White Rodgers Model 36E36
Gas Control |
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INLET |
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Pressure Regulator
Adjustment (Under
Cap Screw)
Inlet Pressure Tap
Figure 38
Robertshaw Model 7222
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