Initial startup and lighting (communicating furnace)

What happens, in order

1. Remove the burner compartment control access door.
2. Confirm the manual gas control has been OFF for at least five minutes. Do not light the main burners by hand.
3. Turn off furnace power and set the thermostat to its lowest setting.
4. Turn the gas control to ON.
5. Replace the burner compartment access door.
6. Turn on furnace power.
7. Set the thermostat above room temperature to call for high stage heat. Setpoint is generally more than 2 F above room temperature. Check thermostat specs.
8. Run high gas heat for at least 15 minutes. Adjust input rate and check the condensate system for leaks. Fix leaks, set rate, shut down, and repeat until no leaks are found.
9. After high heat is verified and the rate set, set the thermostat to call for low stage, generally about 1 F above room temperature.
10. Run low gas heat for at least 15 minutes. Adjust input rate and check the condensate system for leaks again. Fix leaks and repeat until none are found.

Timings and thresholds

More Rheem furnace sequences

• Gas heat call, direct spark ignition and retry · Ignition
• Gas heat call, hot surface ignition and retry · Ignition
• Gas heat call, ignition and retry (direct spark) · Ignition
• Heating ignition and blower sequence · Ignition
• Retry sequence when burners do not light or flame is not sensed · Ignition
• Two-stage gas heat call, ignition on high fire and retry · Ignition
• Two-stage heat call, high-fire light-off and staging · Ignition
• Heating call sequence of operation (Honeywell integrated control, direct spark ignition) · Heating