THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
PLC Communication is very reliable in most applications but can be affected and hindered by connection method used, electrical layout of the application, operation of other equipment in the same electric system, dirty power, etc. If heater(s) and/or receivers are not receiving proper signals from the transmitting device, verify that all heaters/receivers are set to the same channel as the transmitting device. If they are, try a different channel of communication or change phases at the breaker for the heater/receiver which is not getting a consistent signal.
Possible sources of PLC signal interference are solar arrays and invertors, invertor driven well pumps, electric car chargers, appliances, mini-split heat pumps, and other devices that involve power conversion. To troubleshoot, it is often not enough to turn the device off and they should be electrically disconnected from the system at the circuit breaker or disconnect. How long they should remain off is dependent on how often the PLC Fail error is displayed, i.e. more intermittent problems will take more time to prove. You may need to contact the manufacturer of the offending equipment for resolution.