warning - Docs.hvacpartners.com

!CAUTIONFURNACE OVERHEATING HAZARDFailure to follow this caution may result in reduced furnacelife.Recheck temperature rise. It must be within limits specifiedon the rating plate. Recommended operation is at themid -point of rise range or slightly above.c. Proceed to “Set Blower Off Delay” before installingblower door.Adjust Thermostat Heat Anticipatora. Mechanical thermostat. Set thermostat heat anticipator tomatch the amp. draw of the electrical components in theR -W/W1 circuit. Accurate amp. draw readings can be obtainedat the wires normally connected to thermostat subbaseterminals, R and W. The thermostat anticipator shouldNOT be in the circuit while measuring current.(1.) Set SW-1 (LHT) switch on furnace control boardto ON.(2.) Remove thermostat from subbase or from wall.Check Safety ControlsThe flame sensor, gas valve, and pressure switch were all checkedin the Start-up procedure section as part of normal operation.1. Check Main Limit SwitchThis control shuts off combustion system and energizes aircirculatingblower motor, if furnace overheats. By using thismethod to check limit control, it can be established that limitis functioning properly and will operate if there is a restrictedreturn -air supply or motor failure. If limit controldoes not function during this test, cause must be determinedand corrected.a. Run furnace for at least 5 minutes.b. Gradually block off return air with a piece of cardboard orsheet metal until the limit trips.c. Unblock return air to permit normal circulation.d. Burners will re-light when furnace cools down.2. Check Pressure Switch(es)This control proves operation of the draft inducer blower.a. Turn off 115 -v power to furnace.b. Disconnect inducer motor lead wires from wire harness.c. Turn on 115 -v power to furnace.d. Set thermostat to “call for heat” and wait 1 minute. Whenpressure switch is functioning properly, hot surface ignitershould NOT glow and control diagnostic light flashes astatus code 32. If hot surface igniter glows when inducermotor is disconnected, shut down furnace immediately.e. Determine reason pressure switch did not function properlyand correct condition.f. Turn off 115 -v power to furnace.g. Reconnect inducer motor wires, replace outer door, andturn on 115 -v power.h. Blower will run for 90 seconds before beginning the callfor heat again.i. Furnace should ignite normally.Checklist1. Put away tools and instruments. Clean up debris.2. Verify that the jumper is removed from the TEST/TWINterminal. Verify that there is nothing plugged into the PLTconnector. (Note: If there is a jumper connector pluggedinto PLT, remove it and discard.) See Figure (insert circuitboard layout figure number).3. Verify that Heating Operating Mode switch SW-1 is setproperly. See Figure (insert circuit board layout figurenumber).4. Verify that the Blower/Heat Off Delay SW-2 and SW-3switches are set as desired. See Figure (insert circuit boardlayout figure number).5. Verify that the blower and control (“Main”) doors areproperly installed.1/2” NPT Inlet1/8” NPT InletPressure TapON/OFF SwitchTWO-STAGEFig. 51 - Gas ValveRegulator Seal CapRegulator AdjustmentRegulator Seal Cap under Cap1/8” NPT ManifoldPressure Tap1/2” NPT OutletA1115259TP5A61