Troubleshooting - Bryant TSTATBBPSP2-WC Installation, Start-Up And Service Instructions Manual

PROBLEM
Display on thermostat not
illuminated.
Cooling will not energize.
Heating will not energize.
When using 4 wires (R,G,W,Y), the cooling equip-
ment tries repeatedly to turn on, but cannot. At
times the display dims or disappears.
When using 4 wires (R,G,W,Y), the heating equip-
ment tries repeatedly to turn on, but cannot. At
times the display dims or disappears.
When controlling a heat pump, heat comes on
during cooling cycle.
When calling for cooling,
both heating and cooling are energized.
When controlling a commercial heat pump unit,
unit runs in reverse or heating is
always on.

TROUBLESHOOTING

Table 4 — Troubleshooting
Check for 24 vac at the R terminal connection. Terminal R must be connected
for proper thermostat operation.
Select COOL mode. Decrease cooling set point to 10 degrees below room tem-
perature. Check for 24 vac at Y1 terminal. If present, thermostat is operating
correctly and problem is with wiring or equipment. If 24 vac is not present, re-
place the thermostat. Check for Compressor Cycle per Hour Limit. Cooling may
be locked out.
Select HEAT mode. Increase heating set point to 10 degrees above room tem-
perature. Check for 24 vac at W1/O/B terminal. If present, thermostat is operat-
ing correctly and problem is with wiring or equipment. If 24 vac is not present,
replace the thermostat.
There is not enough power available. Connect a 270 ohm, 10 watt power resis-
tor at the air conditioning equipment between terminals W and C (non-heat
pump applications only).
There is not enough power available. Connect a 270 ohm, 10 watt power resis-
tor at the air-conditioning equipment between terminals Y and C (non-heat
pump applications only).
Configure thermostat for heat pump operation
(Table 2, Step 5).
The thermostat is configured for a heat pump. Configure the thermostat for non-
heat pump operation (Table 2, Step 5).
Some commercial heat pumps require that Heat Pump Option on thermostat is
turned OFF. Refer to unit installation instructions for more information.
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SOLUTION