IOM-WR-Radiant_Thermostat-59 324
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Testing the Power
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If the thermostat display turns on, this indicates that the thermostat is operating correctly
and there are no electrical issues. In the event that the display is permanently off:
. Remove the thermostat front.
2. Use an electrical meter to measure voltage between the R and C wiring
terminals. For AC power supplies the voltage should measure between 0 to
30 V (ac). For DC power supplies the voltage should measure between 0 to
30 V (dc).
3. If the voltage on the R and C wire terminations is continuous and the
thermostat display is not on, the thermostat may have a fault. Contact your
Watts Radiant sales representative for assistance.
If the thermostat display initially powers on but later shuts off intermittently, there
may be a short circuit from the W wire to ground, or the power supply is too small
to power the load.
Testing the Heat Zone Output Wiring
---------------------------------
. Touch the button and set the heating temperature above the current room
temperature. Make sure the display does not flash “Max” if using a floor
sensor.
2. When the “Heat On” symbol appears on the display, use an electrical meter
to check for voltage on the W and C wires connected to the zone valve,
wiring center, relay or switching relay. The electrical meter should read 0 to
30 V (ac) or (dc).
3. If the W and C wire have voltage, check the zone valve, wiring center, relay
or pump to determine if the heat device is operating correctly.
Switching Relay
----------------------------------------------------
C
518
R
Rh W1 S1
Com
No Power
R
W
24 V
R
W
H
N
X
X
H
N
H
N
N
H
Com
Switching Relay
Zone 1
Zone 2
Zone 3
Class 2
Transformer
R
W
Zone 1 Zone 2
Zone 3
C
519
R
Rh W1 S1
Com
No Power
L
N
Pump
Floor
Sensor 079
Testing the Thermostat Wiring
