8
9
SYMPTOM POTENTIAL SOLUTION
Thermostat will not
allow me to program
a setpoint
temperature higher
than 90˚ F (32˚ C).
This is above the normal thermostat temperature setting range
of 45˚ to 90˚ F (7˚ to 32˚ C).
Thermostat will not
allow me to program
a setpoint
temperature lower
than 45˚ F (7˚ C).
This is below the normal thermostat temperature setting range
of 45˚ to 90˚ F (7˚ to 32˚ C).
Fan continues to run
all the time whether
the system is on
or off.
Check that the fan control switch is in the AUTO position. This
will allow the fan to run only when the heating or cooling system
is turned on and running.
Check thermostat wiring to make sure that the fan control
wiring is connected to the correct terminals on the wiring
terminal block. See Installation and Wiring Diagrams sections of
this manual.
The room is too
warm or too cold.
See Review Set Temperature section of this manual to verify the
current setpoint and make any modifications that are necessary.
LO is shown in the
thermostat display
where the room
temperature is
normally displayed.
HI is shown in the
thermostat display
where the room
temperature is
normally displayed.
The temperature sensed by the thermostat is higher than the
90˚ F (32˚ C) upper limit of the thermostats display range. The
display will return to normal after the sensed temperature
lowers within the 45˚ to 90˚ F (7˚ to 32˚ C) display range. Turn on
the cooling system or use other methods to lower the
temperature accordingly.
This condition could occur from the system being turned off
during an exceptionally warm period or upon installation when
the thermostat has been stored for a long period of time in a
warm vehicle or location prior to being installed. The thermostat
is equipped with a mechanical high temperature safety switch
that will turn off the thermostat should the temperature exceed
99˚ F (37˚ C) in the heat mode.
TROUBLESHOOTING
6
cont.
WIRING DIAGRAMS
7
Typical 2-Wire 24 Volt AC or 250mV - 750mV Millivolt Heating Systems
Rc Rh GWY
B O
Remove
Factory Installed
Jumper
Heat
Control
24 Volt AC
Transformer
or Thermopile
120
Volt AC
Hot Side
Transformer
TROUBLESHOOTING
6
cont.
SYMPTOM POTENTIAL SOLUTION
Thermostat display
is blank.
It is possible that the batteries are drained and not providing
power for the thermostat to control the system. Replace
batteries immediately to maintain proper system operation. See
Low Battery Detection and Replacement section of this manual.
If you replace the batteries and the display does not appear, call
a professional service technician to verify thermostat and
system performance.
The temperature sensed by the thermostat is lower than the
45˚ F (7˚ C) lower limit of the thermostats display range.
The display will return to normal after the sensed temperature
rises within the 45˚ to 90˚ F (7˚ to 32˚ C) display range. If the
temperature in the controlled space seems to be normal, wait for
the thermostat to acclimate to the correct room temperature.
If the room seems to be colder than usual, turn on the heating
system to raise the temperature as needed for comfort within
the room.
This condition could occur from the system being turned off
during a cold weather period or upon installation when the
thermostat has been stored for a long period of time in a cold
vehicle or location prior to being installed. The thermostat should
be allowed to warm up prior to installation to allow proper
heating control once installed.