York DF078 Series User's, Maintenance And Service Information Manual

Contents

035-19047-002-A-11034 Unitary Products GroupEXPLAIN UNIT FUNCTIONWhen the system is functioning properly, show theowner the location of all disconnect switches and thethermostat. Explain how to start and stop the unit andhow to adjust temperature settings within the limitationsof the system. Advise that the flue exhaust hood sur-face and the immediate area will experience high tem-peratures during the heating cycle, and that allunauthorized personnel and debris must be kept awayfrom this area.GENERAL MAINTENANCEIn order to insure long and trouble free service fromyour system, we recommend periodic inspection,cleaning, lubrication and adjustment by your installingDealer/Contractor. Be sure to ask about this service.For those who prefer to do-it-yourself, please follow theinstructions listed below to care for your system.Snow or debris should not be allowed to accumulate inor around the unit. Do not permit overhanging struc-tures or shrubs to obstruct outdoor air discharge, com-bustion air inlets or vent outlets on your unit. Theseprovide air for combustion and ventilation. Adequate airis important to the safe and proper operation of theunit.HEATING SYSTEM INSPECTIONIt is the owner's responsibility to insure that an annualinspection of the entire heating portion of the unit ismade by a qualified service technician. This shouldinclude inspection of the burner, heating element andflue for any corrosion or soot accumulation which mayrequire cleaning and also checking of burner and con-trols for proper operation.In addition, at least once during the heating season,the owner shall make a visual inspection of the flue out-let for evidence of black soot or blockage of flue outletby leaves or other debris. If any soot is found, it is rec-ommended a qualified service technician be calledimmediately. If any blockage is found, it must becleared immediately.Check for obvious signs of deterioration of the unit.Check that the return and supply ducts attached to theunit are sound and air tight. Check that the unit's physi-cal support, concrete slab or roof curb, is sound andnot in need of repair. Make sure there are no gapsbetween the roof curb and the unit where rain couldleak into the building.Start the furnace. The vent motor should start, theigniter will start to spark and ignite the burner. If it doesnot, contact a qualified service technician for assis-tance. Check the appearance of the main burner flame.The flame should have a blue appearance. (See Fig-ure 3.)BURNER CHECKPeriodically (at least annually at the beginning of eachheating season) make a visual check of the mainburner flame to determine if the burners need cleaning.CLEANING BURNERSRemove them from the furnace as explained the inBURNER/ORIFICE INSTRUCTIONS section in theUnit Installation Instructions. Clean burners with wirebrush and vacuum as needed.CLEANING FLUE PASSAGES & HEATING ELEMENTSWith proper combustion adjustment, the heatexchanger tubes of a gas-fired furnace will seldomneed cleaning. If the tubes should become sooted,they can be cleaned as follows:1. Remove the burner assembly as outlined in“BURNER/ORIFICES INSTRUCTIONS” of the unitInstallation Instructions.2. Remove the screws holding the flue collector box.Carefully remove the flue collector box.3. Remove the flue baffles from the tube interiors.4. Using a wire brush on a flexible wand, brush outthe inside of each heat exchanger from the burnerinlet and flue outlet ends.5. Brush out the inside of the flue collector box andthe flue baffles.6. Run the wire brush into the flue exhaust tube fromthe flue collector end. Do not damage the flueexhaust screen, remove if necessary.7. If soot build-up is particularly bad, remove the draftmotor and clean the wheel and housing.8. After brushing is complete, blow away all brushedareas with air or nitrogen. Vacuum as needed.9. Replace parts in the reverse order that they wereremoved in Steps 1 through 3.10. Assure that all seams on the vent side of the com-bustion system are airtight. Apply a high tempera-ture (500°F+) sealing compound where needed.FIGURE 3- TYPICAL FLAMEHEATEXCHANGERTUBEGASSUPPLYPIPEBURNERBURNERBRACKETIGNITORBURNERLAME(BLUEONLY)