Lux Products P621U operating instructions

outdoor temperatures are too low to support efficient operation, but it could also prevent damage to the heat pump if outside temperatures are below the manufacturer’s recommendations. As every heat pump has different operating characteristics, you should refer to your heat pump literature to determine when to disable the heat pump and run in Emergency Heat mode.

LCD DISPLAY BACKLIGHT: The display screen is lighted to assist viewing at nighttime, or in locations with low light levels. A press of any button on the front panel will light the display for approximately 10 seconds. Any button presses that occur while the light is on will reset the 10-second timer, causing the screen to remain illuminated for an additional 10 seconds.

TEMPERATURE OVERRIDE: While in Program RUN mode, the set temperature can be temporarily changed by pressing UP or DOWN. The set temperature will return to the programmed value stored in memory when the start time of the next upcoming program period is reached (Morn, Day, Eve, Nite). While a Temporary Override is in effect, the word “OVERRIDE” will be shown in the display screen. An Override may be cancelled moving the mode switch to OFF, then back to HEAT or COOL.

MINIMUM RUN TIME: The thermostat has a default internal time delay of 5 minutes between load-on and load-off activations to prevent heating or cooling system damage, which can occur from very frequent cycling. If heating or cooling does not turn on right away with a manual change in set temperature, please wait at least 5 minutes and the system should resume normal operation.

TEMPERATURE HOLD: A Temperature Hold is used for maintaining a fixed set temperature. Once a Hold is initiated, the thermostat will maintain the set temperature indefinitely. A Hold may be used for days, weeks, or even months at a time, as long as the thermostat has adequate power. To enter Hold mode: press the HOLD button one time and the word “HOLD” will appear in the display. To cancel a Hold, press the HOLD button one more time. If a complete power failure occurs during a Temperature Hold, the thermostat will continue to remain in Hold mode even after the power comes back on. NOTE: If you plan to leave the thermostat in Hold mode for an extended duration (unattended), it is advisable to install new Energizer® or DURACELL® "AA" size alkaline batteries prior to leaving to ensure reliable operation of your heating and cooling system.

STATIC NOTICE: This thermostat is protected against normal static electric discharges, however to minimize the risk of damaging the unit in extremely dry weather, please touch a grounded metal object before touching your thermostat.

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