York DM036 Installation Manual

Also see for DM 036: Technical guide

Contents

York DM036 Installation Manual Manual pdf 42 page image

5011492-XIM-B-081542 Johnson Controls Unitary ProductsManifold Gas Pressure AdjustmentSmall adjustments to the high-fire gas flow may be made byturning the pressure regulator adjusting screw on the automaticgas valve.Adjust as follows:1. Remove the cap on the regulator. It's located next to thepush-on electrical terminals.2. To decrease the gas pressure, turn the adjusting screwcounterclockwise.3. To increase the gas pressure, turn the adjusting screwclockwise.NOTE: The correct manifold pressure for these furnaces is 872± 74 Pa gauge (3.50 IWG ±0.3).Pilot CheckoutThe pilot flame should envelope the end of the flame sensor. Toadjust pilot flame, (1) remove pilot adjustment cover screw, (2)increase or decrease the clearance for air to the desired level,(3) be sure to replace cover screw after adjustment to preventpossible gas leakage.Put the system into operation and observe through completecycle to be sure all controls function properly.Burner InstructionsTo check or change burners, pilot or orifices, CLOSE MAINMANUAL SHUT-OFF VALVE AND SHUT OFF ALL ELECTRICPOWER TO THE UNIT.1. Remove the screws holding either end of the manifold tothe burner supports.2. Open the union fitting in the gas supply line just upstreamof the unit gas valve and downstream from the mainmanual shut-off valve.3. Remove the gas piping closure panel.4. Disconnect wiring to the gas valves and spark ignitors.Remove the manifold-burner gas valve assembly by liftingup and pulling back.Burners are now accessible for service.Reverse the above procedure to replace the assemblies. Makesure that burners are level and seat at the rear of the heatexchanger.Burner Air Shutter AdjustmentAdjust burner shutters so no yellow flame is observed in theheat exchanger tubes.Checking Gas InputNatural Gas1. Turn off all other gas appliances connected to the gasmeter.2. With the furnace turned on, measure the time needed forone revolution of the hand on the smallest dial on themeter. A typical gas meter usually has a 1/2 or a 1 cubicfoot test dial.3. Using the number of seconds for each revolution and thesize of the test dial increment, find the cubic feet of gasFigure 21: Typical Gas ValvesFigure 22: Proper Flame AdjustmentFigure 23: Typical Flame Appearance