To Turn Off Gas To Unit
1- Set thermostat to lowest level.
2- Turn off all electrical power to unit if service is to be performed.
3- Honeywell VR8205 series valve: turn knob on gas
valve 90° clockwise 
to OFF.
White Rodgers 36E series valves: turn knob on gas valve 180° either way to OFF.
Robertshaw DER2000 series valves: depress knob on gas valve; knob will snap to OFF.
Heating Sequence of Operation
1- When the thermostat calls for heat, the combustion air blower starts immediately.
2- Combustion air inducer proving switch proves blower operation before allowing power to the ignition controller. This switch is factory set and no adjustment is necessary.
3- After prepurge of approximately 30 seconds, the spark ignition is energized and the solenoid valves open in the gas valve.
4- The spark then ignites the gas, the ignition sensor proves the flame and the combustion process continues.
5- In the event that the flame is not detected after the first
To interrupt the
6- The burners shall light without noticeable crossover delay. There shall be no flame lifting from the burner heads, flashback or burning within the burner. The flames shall be predominantly blue in color and shall be approximately centered in the tubes with no apparent impingement taking place.
7- The ignition control will energize the fan approximately 45 seconds after ignition is established.
8- After the thermostat demand is satisfied the gas valve is closed; 5 seconds after the demand is satisfied the combustion air blower is shut off.
9- The control center shall shut off the system fan approximately 120 seconds after the gas valve is
Ignition Control LED
The ignition control board contains a green LED which indicates the following:
| TABLE 5 |
| IGNITION CONTROL LED |
LED | UNIT OPERATION |
|
|
|
|
Slow | Normal Operation - No call for heat |
Flash* |
|
Fast | Normal Operation - Call for heat |
Flash | Current signal at FLAME terminal 0.6 to 1.0 microamps |
2 Flashes | System lockout - failed to detect or sustain flame |
| Current signal at FLAME terminal <0.6 microamps |
3 Flashes | Combustion air inducer proving switch failed closed |
| before CAB is energized or failed open after CAB is |
| energized |
4 Flashes | High limit or rollout switch open |
|
|
5 Flashes | Flame sensed and gas valve not energized |
|
|
Steady | Loss of power |
Off |
|
Steady | Ignition control failure |
On |
|
*When thermostat is placed in continuous fan mode LED will slowly flash.
Optional Gas Conversion Kit
A natural to LP/propane gas changeover kit is required to convert unit. Refer to the installation instructions supplied with the changeover kit for conversion procedure.
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