UZC4--Fan is running but compressor will not start

[glastar]

I have a problem with a geothermal system using the UZC4 with three zones and two stages. Occasionally, in "Heat" mode only (this never happens in "Cool" mode), the thermostats will call for heat but the compressors will not start. The fan will be running constantly (even though set to "Auto") when this occurs. So far, the only fix is to turn off the system at all three thermostats, let the system power down and the fans shut off, then restart. The system then returns to normal operation. This process always works, however, if the customer is not home, the house will have no heat until this manual shutdown occurs. Any ideas?

[Pcyrana]

Can you tell me every light that's lit on the board when this problem occurs?
Also can you tell me how the dipswitches are set?