Carrier 38CKC042 Air, 38CKC048 Performing Routine Maintenance, Heating Mode, Check the AIR Filter

Fig. 4—Main Electrical Disconnect

or MODE control is set to OFF. With the SYSTEM or MODE control set to COOL, your air conditioner will operate when the indoor temperature rises above the level that you wish to main- tain. With the SYSTEM or MODE control set to HEAT, the heat- ing unit of your home comfort system will operate automatically when indoor temperature falls below the level that you have selected.

The AUTO selection found on some thermostats provides for automatic changeover between cooling and heating equipment operation. With the SYSTEM or MODE control set to AUTO, your air conditioner will operate when the indoor temperature rises above the thermostat cooling temperature setting, or the heating section will operate when the indoor temperature drops below the thermostat setting for the heating cycle.

Your thermostat may be PROGRAMMABLE or NON-PRO- GRAMMABLE. A NON-PROGRAMMABLE thermostat does not allow the temperature settings to be varied throughout the day or week without physically changing the settings. A PROGRAMMABLE thermostat allows various daily tempera- ture changes to be preset. During the winter, for example, you may wish to set back the temperature of your home at night, then have the temperature return to normal prior to waking up. The home’s temperature can then be lowered again during the day when no one is at home, but again be at peak comfort level when your family returns home. During the summer, the opposite changes might be programmed. When properly used, the pro- gramming can result in energy savings on your home’s heating and cooling.

HEATING MODE

With the SYSTEM or MODE control of your indoor thermostat set to HEAT, the heating unit of your home comfort system oper- ates until room temperature is raised to the level you have select- ed. Of course, the heating unit will have to operate for longer periods to maintain a comfortable environment on cooler days and nights than on moderate ones.

Refer to your heating unit User’s Manual for specific informa- tion on heating operation.

PERFORMING ROUTINE

MAINTENANCE

With the proper maintenance and care, your air conditioning unit will operate economically and dependably. Maintenance can be accomplished easily by referring to the following directions.

However, before performing maintenance, consider these important safety precautions:

!WARNING

To prevent personal injury or death disconnect all electrical power to the indoor air handler or furnace before removing access panels or per- forming any maintenance. Disconnect power to both the indoor and outdoor units. NOTE: There may be more than 1 electrical disconnect switch.

!CAUTION

Although special care has been taken to minimize sharp edges in the construction of your unit, be extremely careful when handling parts or reach- ing into the unit.

CHECK THE AIR FILTER

A dirty air filter will cause excessive strain on the compressor and blower motor. This can cause the components to overheat and automatically shut down. In the worst case, these compo- nents will fail and need to be replaced. To avoid inefficient or

COOLING MODE

When operating in cooling mode, your air conditioner runs until the indoor temperature is lowered to the level you have selected. On extremely hot days, your conditioner will run for longer periods at a time and have shorter off periods than on moderate days.

The following are typical conditions that add extra heat and/or humidity to your home and force your cooling unit to work longer to keep your home comfortable:

•Entrance doors are frequently opened and closed.

•Laundry appliances are being operated.

•A shower is running.

•More than the usual number of people are present in the home.

•More than the normal number of electric lights are in use.

•Drapes are open on the sunny side of the home.

Fig. 5—Removing Filter from Fan Coil Unit

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