VARIABLE FREQUENCY DRIVE (VFD)
When the heater is connected to power, the VFD green LED should show 'rdY' ('Ready') after the heater has been plugged in for at least 20 seconds.
When the Supply Fan starts running and blowing air from the outlet, the display will display '0' (zero), and then a quickly increasing value representing the motor speed (in Hz), and should reach '60' in a few seconds. Three speed models will run at, and display, their low, standard, or high speed (50, 55, or 60 Hz)
PLC (ZELIO SMART RELAY)
The Controller is inside the Control Panel junction box. The PLC has a four-line LCD with a backlight. Any button press activates the backlight for a short time. Various information screens appear on the LCD as the controller operates the heater in various modes and stages of operation. THE LCD SHOWS IMPORTANT INFORMATION AND ERROR MESSAGES TO THE OPERATOR THE HEATER STATUS AND TO ASSIST IN TROUBLESHOOTING.
GAS BURNER (RIELLO)
If the heater uses a Riello brand gas burner, there is a indicator circle on the burner controller's housing. The circle mechanically switches to different colors to indicate status. Here is the color code meanings. This listing follows a normal burner cycle:
AMBER - SOLID Pre-Purge
AMBER - FLASH Trial for Ignition
GREEN - SOLID Burner firing
OFF - No Color Burner Off
OIL BURNER (BECKETT)
RESET / LOCK OUT - Red LED Pushbutton, indicates lockout (RED) or hard lockout (FLASHING RED). Press to 1 second to reset Lockout. Press 30 seconds to reset Hard Lockout.
PUMP PRIME - Yellow LED indicator. Unit has been set to, and is running in, Pump Prime Mode. Press Red LED Pushbutton to exit Pump Prime Mode. See manual for how and why to run Pump Prime mode.
FLAME - Green LED Indicator. When the CAD cell ('Flame Eye') detects flame (i.e., visible light), the controller illuminates the Green Flame LED indicator.