York Rooftop Units: ZF, DM
Re: Unit Control Board - Diagnostic Codes
There are two control boards on this unit. The main unit controller mounted in the electrical control panel and the ignition control board mounted in the burner section.
| Unit Control Fault Indicators | |
| On | Control Failure - Replace Control |
| Pulse | Normal Operation |
| 1 Flash | Not Applicable |
| 2 Flash | Control waiting (short-cycle delay) |
| 3 Flash | Compressor 1 HPS Lockout |
| 4 Flash | Compressor 2 HPS Lockout |
| 5 Flash | Compressor 1 LPS Lockout |
| 6 Flash | Compressor 2 LPS Lockout |
| 7 Flash | Compressor 1 FreezeStat Lockout |
| 8 Flash | Compressor 2 FreezeStat Lockout |
| 9 Flashes* | Ignition Control Fault |
| 10 Flashes | Compressor 1 off due to Low OA Temp |
| 11 Flashes | Compressor 2 off due to Economizer |
| 12 Flashes | Fan Overload Tripped |
| 13 Flashes | Low Voltage Detected |
| 14 Flashes | Control Failure |
| Off | No Power or Control Failure |
* Code 9 - You must check the Ignition Control Board for the actual fault condition.