43
QM 1336.rev.01
TROUBLESHOOTING GUIDE
CAUSE
SOLUTION
PROBLEM
There is no
display.
The circuit breaker at
the service panel is
off or tripped.
Correct the problem and reset
the circuit breaker.
The wiring is incor-
rect.
Correct the wiring.
The voltage selector
switch is in the
wrong position.
Set the switch to the correct
position.
The display board
interconnect cable is
not properly plugged
into the power supply
board.
Be sure the cable is firmly
plugged in.
The display
shows "P" when
the parameter
selection knob is
set to ROOM.
A room probe is
connected improp-
erly.
Correct the room probe connec-
tion.
A room probe is
defective.
Refer to "defective probes"
The defective
probe pilot light
is on.
A room or outside
probe is defective.
Refer to "defective probes"
