Kärcher HDS4.0/22 Dealer's Manual

Also see for HDS 3.9/30: Operator's manual Operator's manual

Contents

26MaintenanceMaintenance & ServiceSpray Nozzles:Each machine is equipped with one or more spraynozzles, depending on the model. Different spraynozzles are calibrated for each machine, depending onthe flow and pressure of that particular model. Spraynozzles vary in bore size and angle of spray. Popularspray angles are 0°, 15°, 25°, 40°. When ordering,please specify size and angle of nozzle. Nozzle size foreach machine is located on the serial plate.Unloader Valves:Unloader valves relieve pressure in the line when aspray gun is closed. Unloader valves are preset andtested at the factory before shipping. Occasionaladjustment of the unloader may be necessary tomaintain correct pressure. For valve adjustmentcontact your nearest dealer or call technical support.Tampering with the factory setting may cause personalinjury and/or property damage, and will void the manu-facturer's warranty.Winterizing Procedure:Damage due to freezing is not covered by warranty.Adhere to the following cold weather procedureswhenever the washer must be stored or operatedoutdoors under freezing conditions.It is necessary to protect your machine against freezingwhen temperatures drop below 32° F. Siphoning asmall amount of antifreeze into the system is recom-mended. This is done by pouring a 50-50 mix of anti-freeze and water into the float tank and then siphoning100% antifreeze through the detergent line with thepump on. If compressed air is available, an air fittingcan be screwed into the float tank strainer fitting, and byinjecting compressed air, all water will be blown out ofthe system. The use of a draft diverter will prevent thewind chill factor from freezing the coil.Low Pressure Diagnosis:(Machines with spray gun)Refer to Troubleshooting Chart for low pressure. If thetrouble is found to be either the unloader or the pump,your next step is to determine which is the problem.This can be done by eliminating the unloader from thesystem and attaching the 50' discharge hose directly tothe pump. If high pressure is developed in this manner,the pump is good and the unloader needs to berepaired or replaced. If low pressure is still present,then the pump needs repairing.CAUTION: When using this procedure to testcomponents keep the spray gun open at all times.High Limit Hot Water Thermostat:For safety, each machine is equipped with a high limitcontrol switch. In the event the temperature of the watershould exceed its operating temperature, the high limitcontrol will turn the burner off until the water cools.Pumps:Use only SAE 10W-40 non-foaming oil. Change oil afterfirst 50 hours of use. Thereafter, change oil every yearor at 500 hour intervals. Oil level should be checkedthrough use of the dipstick found on the top of the pumpor by the red dot visible through the oil gauge window.Oil should be maintained at that level.Heating CoilsTo Check Water Heater Coil for Leaks:With the main burners “OFF” start the pumping unit andallow it to run for a few minutes. Check into the burnercompartment with a drop light or flashlight. If no leaksare visible, then water dripping from coils is condensa-tion from the flue gases when the burners are on.Condensation from Heating Coil:When cold water is being pumped into the water heatercoils, and the burners are on, condensation will form onthe coils and drip down into the burner compartment,giving the appearance of a leaking coil, particularly oncold humid days.Descaling Coils:In alkaline water areas, lime deposits can accumulaterapidly inside the coil pipes. This growth is increasedby the extreme heat build up in the coil. The bestprevention for liming conditions is to use high qualitycleaning detergents. In areas where alkaline water isan extreme problem, periodic use of Karcher CoilDescaler (part # 9.803-742.0) will remove lime andother deposits before coil becomes plugged.Periodic descaling of the heating coil isrecommended so please consult your local LandaDealer for instructions.Karcher Liberty HDS Stationary Dealer’s Manual 9.801-508.0 - AY