Troubleshooting; Error Codes; Comm Error; Hw Failure - cor thermostat 5 Installation Instructions Manual

TROUBLESHOOTING

If the display module doesn't power up after power is applied, check the Rc/Rh and
C terminals for 24VAC. If 24VAC is present, check the voltage between Vg and
V+. This voltage will be approximately 12−20VDC. If voltage is present, check the
polarity to make sure it is wired correctly. The display will not power up if polarity
is reversed.
If dashes appear for SW01 in config and during reboot, the problem could be the
red pigtail being wired to Rc or Rh and the black pigtail being wired to C. If so,
remove the two−wire pigtail and connect to the V+ and Vg terminals.

Error Codes

Comm Error − If the Côr 7 Series Thermostat and the Two−Wire Relay Module
cannot communicate via two−wire connection, an Comm Error will be displayed.
HW Failure − If Côr 7 Series Thermostat's internal memory fails, HW Failure will
be displayed. Replace Thermostat.
Invalid HUM − If Côr 7 Series Thermostat cannot properly read humidity, Invalid
HUM will be displayed. Replace Côr 7 Series Thermostat. If both Humidify and
Dehumidify have been set to OFF, the humidity value will be shown as "−−" when
viewed from the humidity menu, but no Invalid HUM will be shown in the display.
Table 4 can be used as a troubleshooting tool for determining which outputs will be
active for a particular configuration and each operating mode. When replacing a
failed component such as an equipment control module or a display module, the
installer should replace both parts as a matched set. It is very easy to accidentally
mix an A/C or HP display with a PRH equipment control module. When this
happens, some functions appear in the setup while others do not. This can be very
confusing to troubleshoot. Verify that both parts have the same model and serial
number when troubleshooting the thermostat.
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