Lennox International Inc 4HP18LT manual Homeowner Information, Inspect and clean outdoor coil

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HOMEOWNER INFORMATION

In order to ensure peak performance, your system must be properly maintained. Clogged filters and blocked airflow prevent your unit from operating at its most efficient level.

WARNING

Turn all electric power to unit OFF at disconnect switch(es) before performing any maintenance operations on system. Unit may have multiple power supplies. Electrical shock could cause personal injury or death.

Ask your dealer to show you where the indoor unit’s filter is located. It will be either at the indoor unit (installed internal or external to the cabinet) or behind a return air grille in the wall or ceiling in your home. Check the filter monthly and clean or replace it as needed.

Disposable filters should be replaced with a filter of the same type and size. If you are unsure of the filter you need for your system, contact your dealer.

Many indoor units are equipped with reusable foam filters. These filters can be cleaned with a mild soap and water solution. Rinse the filter thoroughly and let dry completely before returning to unit or grille.

The filter and all access panels must be in place any time the unit is in operation.

Some systems are equipped with an electronic air cleaner, designed to remove the majority of airborne particles from the air passing through the cleaner. If your system includes an electronic air cleaner, ask your dealer for maintenance instructions.

Inspect and clean indoor coil. The indoor evaporator coil is equipped with a drain pan to collect condensate formed as the system removes humidity from the inside air. Have your dealer show you the location of the drain line and how to check for obstructions. This also applies to an auxiliary drain, if one is installed.

Inspect and clean outdoor coil:

Make sure no obstructions restrict airflow to the outdoor unit. Leaves, trash, or shrubs crowding the unit can cause it to work harder and use more energy. Keep shrubbery trimmed away from the unit and periodically check for debris which collects around the unit.

The outdoor coil may require frequent cleaning, depending on environmental conditions. Clean the outdoor coil with an unpressurized water hose to remove surface contaminants and debris. It may be necessary to flush the outdoor coil

more frequently if it is exposed to substances which are corrosive or which block airflow across the coil (such as pet urine, cottonwood seeds, etc...).

Heat Pump Operation

Heat pump units have several characteristics you should be aware of:

Heat pumps satisfy heating demand by delivering large amounts of warm air into the living space. This is quite different from gas-fired, oil-fired, or electric furnaces which deliver lower volumes of considerably hotter air to heat the space.

Do not be alarmed if you notice frost on the outdoor coil in the winter months. Frost develops on the outdoor coil during the heating cycle when temperatures are below 45°F. An electronic control activates a defrost cycle lasting 5 to 15 minutes at preset intervals to clear the outdoor coil of the frost. A shift in sound type does occur during the defrost mode.

During the defrost cycle, you may notice steam rising from the unit. This is a normal occurrence. The thermostat may engage auxiliary heat during the defrost cycle to satisfy a heating demand. The unit will return to normal operation at the conclusion of the defrost cycle.

In case of extended power outage....

If the outdoor temperature is below 50°F and power to the outdoor unit has been interrupted for 6 hours or longer. observe the following when restoring power to the heat pump system.

Set the room thermostat selctor to the “Emergency Heat” setting to obtain temporary heat for a minimum of 6 hours. This will allow system refrigerant pressures and temperatures enough time to return to a stabilized condition.

In the “Emergency Heat” mode, all heating demand is satisfied by auxiliary heat; heat pump operation is locked out. After a 6 hour “warmup” period, the thermostat can then be switched to the “Heat” setting and normal heat operation may resume.

Thermostat Operation

Though your thermostat may vary somewhat from the description below, its operation will be similar.

Temperature Setting Levers

Most heat pump thermostats have two temperature selector levers: one for heating and one for cooling. Set the levers or dials to the desired temperature setpoints for both heating and cooling. Avoid frequent temperature adjustment; turning the unit off and back on before presssures equalize puts stress on unit compressor.

506470-01

Issue 1007

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Contents Save these instructions for future reference Lennox International Inc. CompanyInstallation Installation ClearancesGeneral Torque TableElectrical Wiring Slab MountingSlab Mounting Roof MountingInstalling Refrigerant Line Refrigerant PipingPlacement Outside Unit Placement & InstallationLine Set Isolation Refrigerant Line Set DiametersRefrigerant Line Sets Installing Horizontal Runs Refrigerant Line Sets Transition from Vertical to Horizontal Flushing Procedure Required EuipmentRefrigerant Metering Device Expansion Valve SystemsTo Access the Schrader Port To Close Liquid or Suction Line Service ValveUsing an Electronic Leak Detector EvacuationIssue Refrigerant Charge Adjustment START-UPRefrigerant Charging Issue R410A Temperature/Pressure Chart Approach Values for TXV Systems Issue Operation Defrost Control Timing Pins Compressor DelayTime Delay Pressure Switch CircuitSystem Diagnostic Module Interpreting the Diagnostic LEDsLED Description 24VAC Power Wiring Thermostat Demand Wiring Miswired Module CodesMaintenance Inspect and clean outdoor coil Temperature Setting LeversHomeowner Information Fan Switch System SwitchTemperature Indicator Indicating LightStart-Up and Performance Checklist Wire Diagram Issue