Replacing Old Thermostat/Choosing Location - NOMA THM301M User Manual

Replacing Old Thermostat
Note: Do not operate the cooling system when outside temperature is below 10 C (50 F) to avoid
damaging the compressor.
Test the system to make sure that your heating and cooling are working properly before
installation. If either does not work, contact your local heating/air-conditioning dealer to fix the
problem before installation.
TURN OFF POWER to system at the furnace, or at the fuse/circuit breaker panel.
Carefully unpack your new thermostat and mounting plate; save package of screws, instructions
and receipt.
Remove cover from old thermostat. If it does not snap off when pulled firmly from the bottom,
check for a screw used to secure the cover.
Loosen screws holding thermostat to the wall and lift away the thermostat.
Disconnect wires from old thermostat or sub-base. As you disconnect each wire, use masking
tape to label it with the old terminal designation. If there are only two wires, they don't need to be
labeled. If there is an extra wire that is not connected to your old thermostat, then you won't need
to connect it to the new thermostat.
Take care not to let the wires fall back into the wall or let the ends of the wires touch one another .
The wires are usually designated 'R', 'G', 'Y', 'W', 'Rc', 'C'.
19
To cancel Hold function, press HOLD again. The current scheduled program number (P1 ~ P4).
will appear on the screen and the HOLD symbol will disappear. The thermostat will return to the
programmed temperature.
Check Current Programs
Press either UP or DOWN once to check the current programmed temperature setting without
changing it. You may also use the CURRENT key for this function.
Room Temperature
Press DISPLAY anytime to check the current temperature.
Fan Control Switch
If your heating/cooling system is equipped with a fan, it will be turned on automatically when
heating or cooling is activated.
To turn on the fan manually , set the Fan ON/AUTO switch to the ON position, the fan will run
10
Cooling Programs
Slide the system switch to the COOL position and repeat the programming as you would for the
° °
Heating Programs.
Temporary Override
To change the temperature temporarily , press UP or DOWN to set the desired temperature. The
thermostat will return to the regular program at the next scheduled program time.
Note: The thermostat has an automatic delay function to protect the heating and cooling systems
from undesired on/off sequences. Sometimes there will be a delay of several minutes before the
thermostat will activate the system.
Hold
This feature is to hold the thermostat at a constant temperature and disable the set programs.
Press HOLD once and use UP or DOWN button to set the desired hold temperature. HOLD
symbol will appear to indicate that the Hold function is active.
Choosing Location For New Thermostat
Thermostat should be mounted:
Approximately 5 ft (1.5m) from floor.
Near or in a frequently used room, preferably on an inside partitioning wall.
On a section of wall without pipes or duct-work
Thermostat should NOT be mounted:
Near a window, on an outside wall, or next to a door leading outside.
Exposed to direct light or heat from a lamp, sun, fireplace, or other temperature-radiating
objects which may cause false readings.
Near or in direct airflow from supply registers and return-air grilles.
Near concealed pipes and chimneys
In areas with poor air circulation, such as behind a door or in an alcove.
After choosing a location for the new thermostat, you may arrange to have a heating contractor
install the control wiring for you.
9
18