Troubleshooting: Heating Sequence of Operation (Continued)
CALL FOR HEAT SATISFIED
RUN MODE (TWO−STAGE THERMOSTAT) | 3A | 3B | RUN MODE (SINGLE−STAGE THERMOSTAT) | |
FIRST OR SECOND−STAGE CALL FOR HEAT | ALL INPUTS MONITORED (LIMIT, PRESSURE, | |||
|
| |||
ALL INPUTS MONITORED (LIMIT, PRESSURE, |
|
| CALL FOR HEAT/COOL, FLAME LEVEL). | |
CALL FOR HEAT/COOL, FLAME LEVEL). |
|
|
|
2nd Stage Heat
NO
2nd Stage Call for Heat satisfied?
YES
Combustion Air Inducer
switched to 70% rate speed
Adjust Indoor Blower to appropiate speed
|
|
|
|
|
|
1st Stage Heat |
|
|
|
| |
|
| NO |
| ||
|
| ||||
|
|
|
|
|
|
|
|
|
|
|
|
1st Stage Call for Heat satisfied?
YES
Gas valve
De−Energized
Combustion Air Inducer OFF after 20−Second Post Purge
Indoor Blower OFF
after OFF Delay
1 | OR | 4 |
Wait for Call |
| Wait for Call |
Two−Stage |
| Single−Stage |
Thermostat |
| Thermostat |
Page 59
