- Condition: The dryer has detected the absence of adequate gas pressure to the fuel trane.
- Alarm Action Taken: COOL DOWN
- Component: Gas Pressure Switch.
- Location: On the fuel trane at the base of the dryer before the manual Maxon valve.
Tools Required for Service:
- Voltage/continuity meter
- Small standard blade screwdriver (to remove cover and wiring terminals inside)
- “Shorty” flat blade screwdriver (to adjust setpoint)
Tech tip: (Has a scale reading in Inches of Water Column “WC)
The low gas pressure switch is a microswitch based device that monitors the incoming fuel for adequate gas pressure. It normally can be identified by being one of two pressure switches located on the fuel trane at the base of the dryer with a glass cover with a scale viewable inside.
If the incoming pressure is too low, the microswitch opens up its contacts and triggers the alarm. To adjust the setpoint, remove the right-hand screw in the mounting clip that holds the glass face cover on. Behind the clip is the adjusting screw. Adjust the screw in or out to change the setpoint.
Potential causes of this alarm condition:
- Lack of fuel to dryer
- Shutoff valve not open
- Switch setting too low
- Faulty switch
- Poor or faulty wiring connection