Greenheck Fan VSU Make-Up Air Unit with Direct-Fired Gas Heater 470654 - Manual (Page 34)

34 Model VSU Make-Up Air
®
Typical Gas Train Layout with Direct Spark Ignition
This is a typical gas train. The gas train in your unit may be different.
Reference
Burner Differential
Pressure Sensor
(Airflow Switch)
Modulating
Valve
to Burner
Combination Shut-Off
Valve/Regulator
Low Gas Pressure
Switch (optional)
Low Gas Pressure
Test Port
Gas Connection
High Gas Pressure
Test Port
Burner Manual
Shut-Off Valve