Johnson Controls A419 Troubleshooting Johnson A419 Temperature Controller is designed to control HVAC equipment under normal operating conditions. Where failure or malfunction of a Johnson A419 temp control could cause damage to the equipment or other devices like limit or safety controls. If you have issue with your controller, check out our Johnson Controls A419 troubleshooting tips.
Johnson Controls A419 Troubleshooting Guide Johnson Temperature Control A419 series can be used to control a wide variety of single-stage HVAC or refrigeration equipment. Typical applications include: Retail stores display freezers, walk-in coolers, and reach-in coolers. Space and return air temperature control. Supermarket display cases for products. Cooling tower pump and fan control. Condenser fan cycling or staging. Boiler operating control, used as a thermostat. Johnson A419 Troubleshooting If your Johnson controls A419 not working properly, you have to verify it's wiring, and configuration. Also, check whether it is set properly or not. If all these are in good condition, but the problem persists, try the following procedures to determine the cause of the problem. Check for proper supply voltage to the control To verify if the Johnson temperature control is receiving proper voltage, go through the below steps. Loosen the four captive cover screws for removing the cover. You have to use a reliable AC voltmeter to check the voltage between COM and 120/ 240V terminals on line voltage models. And, verify between the two 24V terminals on low voltage models.