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IOM-T-560 2145
© 2021 tekmar
The Heat On symbol is shown on the display when the thermostat is heating. Heating for freeze protection
is provided whenever the air or floor temperature falls below 40°F (4.5°C), regardless of operating mode.
Regular Heating
W1 relay is on when the air temperature falls 1.5°F (1°C) below the Heat To setting. When the tem-
perature reaches the Heat To setting, the relay turns off.
Radiant Floor Heating
When Radiant Floor Heating is selected in the setup menu, the W1 relay operates using Pulse Width
Modulation. This improves comfort for radiant systems with high mass floors.
• 100% on time at Heat To setting -1.5°F
• 50% on time at Heat To setting
• 0% on time at Heat To s 1.5°F
Room Sensor and Averaging
The room temperature can be measured using a combination of the built-in and auxiliary sensors.
• Built-in room sensor only
• Built-in room sensor with auxiliary room sensor(s) (temperature is averaged)
• Auxiliary room sensor only
Floor Sensor for Radiant Floor Heating
If a floor sensor is connected, floor minimum and maximum settings are available.
For a combination of air and floor temperature control, leave the internal air sensor on in the setup
menu. A floor minimum can be used to prevent a fast drop in temperature caused by receding solar
exposure. This operation is recommended for areas heated by afternoon sun through large windows.
When the sun sets, it can take a long time for the floors to get warm again. This may cause the room
to cool off too much in the early evening. A floor minimum setting can help with this condition by
maintaining a floor minimum temperature. Keep in mind the floor minimum temperature will override
the air temperature, and if set too high, may overheat the room.
A floor maximum is recommended for rooms with hardwood floors. Setting floor minimum and
maximum temperatures is a way of enhancing the comfort of the living space while protecting floor
coverings.
If there are more than one floor temperature sensors, the temperature is averaged.
Warm Weather Shut Down (WWSD)
The heating system can automatically shut off based upon the outdoor temperature and the WWSD
setting. This provides a convenient way to shut off radiant floor heating. The WWSD feature requires
the installation of an Outdoor Sensor 070.
Sequence of Operation
Heating Operation