FORM 2045-2 1306 ©2013 White-Rodgers by Permission
37-6864B
4
WIRING DIAGRAM 3
–
Heat Pump Thermostats
C
O/B
R Y G E
E
G
Y
R
W/O/B
C
CLOSE
OPEN
COM
ZONE
CONNECTIONS
T
HE
RM
O
S
T
A
T
DA
M
P
E
R
Heat Pump Thermostat
WIRING DIAGRAM 4 –
Typical Heat Pump Equipment
Compressor Relay
Reversing Valve
24V. Transformer
Second Stage Heat Relay
Emergency Heat Relay
Fan Relay
EQ
U
IP
M
EN
T
AIR TO AIR HEAT PUMP CONNECTIONS
HEAT PUMP CONTROLS
W2
W1
Y1
Y2
O
G
E
B
R
W3
Compressor Relay
Reversing Valve
24V. Transformer
Second Stage Heat Relay
Emergency Heat Relay
Fan Relay
EQ
U
IP
M
EN
T
AIR TO AIR HEAT PUMP CONNECTIONS
HEAT PUMP CONTROLS
W2
W1
Y1
Y2
O
G
E
B
R
W3
TROUBLESHOOTING
The CZ-4 is a very simple control to troubleshoot, especially with the
LED indicators. The only other device needed is a simple Volt/Ohm
meter. Almost all problems can be traded to an external component
or wiring to the CZ-4. While the CZ-4 has been designed to operate
under extreme voltage conditions and is fuse protected, like any
computer the micro-processor can hang up and not operate properly.
For these instances a BOOT button has been installed that re-boots
the micro-processor just like your computer. Pressing this button for
a few seconds and then release it will allow the micro-processor to re-
boot and in most all cases eliminate the problem. If not the following
procedure can help isolate the problem.
Zone(s) Not Calling
Each zone has a Green LED next to the zone relay when it is calling
and that calling is being recognized by the CZ-4. If a zone is
supposed to be calling and the Zone LED is not on, check for 24VAC
across the thermostat terminal C and the Y, if a Cool call, W if a Heat
Call, or G if a Fan call. If there is no voltage here at the panel the
panel is not getting the signal from the thermostat. The problem is
mis-wiring, a broken wire or a problem in the thermostat. To check
the zone on the panel, place jumper from R to Y, R to W or R to G to
see that the panel is operating properly.
Zone(s) Will Not Shut Off
If a zone will not stop calling, the Zone LED should still be on.
Depending on the call disconnect the Y, W or G wire from the
terminal strip. The zone will drop out. Check the thermostat wiring
for a mis-wiring or short that keeps the zone calling.
Damper Motor Checkout
Each zone has Green indicator light located to the right of the zone
damper’s relay. When all zones are satisfied all zone LEDs are lit
Green indicating all zone dampers will be Open. To check this there
will be 24VAC across the COM and Open terminal. When any zone
calls, the damper(s) to the satisfied zone(s) will power close and the
indicator light will go out. When the damper is to be closed there will
be 24VAC across COM and CLOSE.
St. Louis, MO. Markham, Ontario
www.white-rodgers.com
BOOT
