On the display
The panel shows WATCHDOG - SOFTWARE REBOOT. The message is printed in exactly this wording for this model, and the manuals list it among the Safety shutdown messages: the chiller is shut down and its operating program has been re-initialized.
What it means
The Microboard's software Watchdog detected that a portion of the chiller operating program was not being executed and therefore initiated a reset of the Microprocessor. The result of this reset is a Safety shutdown of the chiller and a re-initialization of the program. In short, the supervisory software on the Microboard stopped the unit because part of the operating program was no longer running, and the processor was reset and started over.
Why it appears
- Severe electrical power disturbance. The manual states that this message is generally indicative of a severe electrical power disturbance.
- Impending Microboard failure. An impending failure of the Microboard is the second condition the manual names as a general indication of this reset.
Reset and restart
Restart takes a single action: place the COMPRESSOR switch in the Stop-Reset (O) position. The manual states: The chiller can be started after the COMPRESSOR switch is placed in the Stop-Reset (O) position.
Once the switch is in that position, the chiller can be started again.
Questions engineers ask
What does WATCHDOG - SOFTWARE REBOOT mean on a YORK YMC2?
The Microboard's software Watchdog reset the Microprocessor because it detected that a portion of the chiller operating program was not being executed. The result is a Safety shutdown and re-initialization of the program.
What causes WATCHDOG - SOFTWARE REBOOT on a YMC2 chiller?
The manual says the message is generally indicative of a severe electrical power disturbance or an impending Microboard failure.
How do I restart the chiller after WATCHDOG - SOFTWARE REBOOT?
Place the COMPRESSOR switch in the Stop-Reset (O) position. After that, the chiller can be started again.
Is WATCHDOG - SOFTWARE REBOOT a safety shutdown?
Yes. The microprocessor reset triggered by the Watchdog results in a Safety shutdown of the chiller, and the program is re-initialized.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YMC2; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YMC2 messages: fault codes · YORK YMC2 documentation · YORK manuals