Lennox International Inc 4HP18LT manual Maintenance

Page 23

MAINTENANCE

WARNING

Before performing maintenance operations on system, turn the electric power to unit OFF at disconnect switch(es). Unit may have multiple power supplies. Electrical shock could cause personal injury or death.

Before the start of each heating and cooling season, the following service checks should be performed by a qualified service technician.

Inspect and clean outdoor and indoor coils. The outdoor coil may be flushed with a water hose.

NOTE: It may be necessary to flush the outdoor coil more frequently if it is exposed to substances which are corrosive or which block air flow across the coil (such as pet urine, cottonwood seeds, etc...).

Visually inspect the refrigerant lines and coils for leakes.

Check wiring for loose connections.

Check voltage at the indoor and outdoor units (with units operating).

Check amperage draw at the outdoor fan motor, compressor, and indoor blower motor. Values should be compared with those given on unit nameplate.

Check, clean (or replace) indoor unit filters.

Check the refrigerant charge and gauge the system pressures.

Check the condensate drain line for free and unobstructed flow. Clean drain line, if necessary.

Adjust blower speed for cooling. Measure the pressure drop over the coil to determine the correct blower CFM.

Belt drive blowers: Check drive belt for wear and proper tensions.

If insufficient cooling is reported, the unit should be gauged and refrigerant charge checked (see Refrigerant Charging on page 13).

506470-01

Issue 1007

Page 23

Image 23
Contents Lennox International Inc. Company Save these instructions for future referenceTorque Table InstallationInstallation Clearances GeneralRoof Mounting Electrical WiringSlab Mounting Slab MountingRefrigerant Piping Installing Refrigerant LineRefrigerant Line Set Diameters PlacementOutside Unit Placement & Installation Line Set IsolationRefrigerant Line Sets Installing Horizontal Runs Refrigerant Line Sets Transition from Vertical to Horizontal Required Euipment Flushing ProcedureExpansion Valve Systems Refrigerant Metering DeviceTo Close Liquid or Suction Line Service Valve To Access the Schrader PortEvacuation Using an Electronic Leak DetectorIssue Refrigerant Charging Refrigerant Charge AdjustmentSTART-UP Issue R410A Temperature/Pressure Chart Approach Values for TXV Systems Issue Operation Pressure Switch Circuit Defrost Control Timing PinsCompressor Delay Time DelayLED Description System Diagnostic ModuleInterpreting the Diagnostic LEDs 24VAC Power Wiring Miswired Module Codes Thermostat Demand WiringMaintenance Homeowner Information Inspect and clean outdoor coilTemperature Setting Levers Indicating Light Fan SwitchSystem Switch Temperature IndicatorStart-Up and Performance Checklist Wire Diagram Issue