| Problem | Possible Solution |
|---|---|
| Unit will not operate, SMX Display Not On | 1. Check circuit breaker. 2. Check voltage, power supply. 3. Check CX/CXP cable and connections. 4. Replace SMX keypad/display. 5. Replace SMX Power/Logic board. |
| Erratic SMX Temperature Display | 1. Perform a Factory Memory Reset. 2. Check temperature sensor, cable and connection. 3. Ensure the temperature sensor is installed properly. 4. Calibrate temperature. 5. Replace Power/Logic board. |
| Erratic SMX operation | 1. Perform a Factory Memory Reset. 2. Check CX/CXP cable and connections. 3. Check temperature sensor, cable and connection. 4. Replace keypad/display. 5. Replace Power/Logic board. |
| Air from the unit does not feel cool | 1. Make sure control is set in Cool mode. 2. Check thermostat setting. 3. Confirm that the compressor is running. 4. Check solenoid valve to see that it is opening. |
| Compressor is not running | 1. Check water flow. 2. Check compressor relay, triggers. 3. Check high and low pressure switches. 4. Check solid state relay |
| Unit blows cool air, but fails to cool the cabin | 1. Check air filter. 2. Check thermostat setting. 3. Check compressor for short-cycling. |
| Compressor cycles on and off | 1. Check water flow. 2. Check high and low pressure switches. 3. Check temperature sensor to make sure it is installed properly and not touching any metal surfaces. 4. Ensure that cooling unit’s discharge air is not blowing directly toward the return air grill. |
| The cooling unit won’t heat | 1. Check that control is in Heat mode, and thermostat is set properly. 2. Enable Aux Heat on the SMX control (if a Factory Memory Reset is performed, Aux Heat will need to be enabled). 3. Check the manual thermal overload on the cooling unit. |
| Water dripping inside cabin | 1. Clean out condensate drain pan and fittings. 2. Clear blockage in drain hose. 3. Check downhill routing of hose. 4. Ensure that insulation around ducting is not compressed or crimped. |
| Condensing unit has frost buildup | 1. This might be a normal occurrence in the modulating system operation. As cooling units shut off, the load on the unit drops and the suction line can frost up. If all cooling units are on, and there is a sufficient heat load, the suction line should not be iced over. 2. Check system charge. |