Applicable Systems
Carrier ComfortLink Thermostat/Controller
Symptoms
Suction pressure low. The suction pressure is below the normal operating range.
Possible Causes
- Refrigerant undercharge
- Expansion valve restricted or faulty
Troubleshooting Steps
- Step 1: Check the suction pressure with gauges
Pressure is below normal range - Step 2: Inspect the expansion valve operation
Valve is restricted or not opening fully
How to Reset
To reset: Fix the charge or expansion valve, then reset the controller.
Source: Carrier HVAC Troubleshooting Guide, Carrier Corporation
Category: HVAC Residential