Atwood Furnaces

Sequence of operation for MOST furnaces.

 

This is generic and applies to most DSI model furnaces.

Your model MAY vary.  Warning:  We recommend that only qualified technicians work on furnaces.
 Do It Yourself at your own risk.
 You are responsible for all safety precautions and leak checking.

Before attempting to trouble shoot your furnace be sure you understand the sequence of operation

•Thermostat calls for heat.
•Thermostat relay or time delay relay is energized and allows power to the blower.
•Blower motor runs up to speed.
•Sail switch closes at 75% of rated blower speed.
•Power goes through the limit switch to the ignition control board.
•The control board begins trial for ignition, opening gas valve and initiating ignition spark.
•Burner ignites.
•Thermostat reaches setting and opens.
•Burner shuts down.
•Fan runs briefly to cool furnace.