Thermo Products CMA2-75N, CMA1-50N service manual The LED will also flash once at power-up

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All installations and services must be performed by qualified service personnel.

3 flashes, then pause	pressure switch stuck open
4 flashes, then pause	open high limit switch
6 flashes, then pause	115 volt AC power reversed
7 flashes, then pause	low flame sense signal
8 flashes, then pause	check ignitor or improper grounding
Continuous flashing	Flame has been sensed when
(no pause)	no flame should be present

(no call for heat)

The LED will also flash once at power-up.

: Power must be disconnected before servicing.

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Contents GAS FIRED HIGH EFFICIENCY FURNACE INSTALLATION AND SERVICE MANUALFOR YOUR SAFETY DOWN FLOW & DIRECT VENT SEALED COMBUSTIONTABLE OF CONTENTS SECTIONI. SAFETY INFORMATION Page Page The vent and air intake elbows must be kept away from bushes, shrubs or any vegetation that may restrict the flow of flue products. It must also be kept clear of any leaves, weeds or other combustible materials. Keep the vent hood clear of snow. Avoid locating the terminals in areas where standing water or condensate drippage may be a problem 1.A windows be opened MODEL II. FURNACE SPECIFICATIONS - CMA SERIESDIMENSIONS GAS SUPPLY PRESSUREINSTALLATION PARTS PACKAGE COMBUSTIBLE MATERIAL.” COMBUSTIBLE MATERIAL NON-COMBUSTIBLEMATERIALMODELS CMA IV. GENERAL INSTALLATION A.FURNACE LOCATIONTable Coil Cabinet Combustible Floor Base Model: 70-BASE Figure 1AFigure 1B Cottage Base Model: 01COT-BASE Figure 1C 1. Combustible Floor Base Model: 70 BASE B. BASE INSTALLATIONFigure Figure 2. Cottage Base Model: 01COT BASE C. ALCOVE INSTALLATIONFigure D. CLOSET INSTALLATION FigureE. FUEL PIPING F.GENERAL VENTING REQUIREMENTS MAXIMUM VENT LENGTH TableFigure 6. CMA*-75SHOWN H. Direct Venting Through a Sidewall 1. Vent And Combustion Air Pipes2. Exhaust Vent Termination Elbow Sidewall Venting Page 4. Vent Terminal Location Guidelines Terminations 5.Secure plate to roof Figure FigureFigure K.CONDENSATE DRAIN LINE AND TRAP ASSEMBLY 3.Connection Of Room Thermostat Wires Figure L.ELECTRICAL WIRING2.Connection Of Power Supply Wires 1. Electrical Branch Supply CircuitElectrical Wire Diameter AWG 24 22 20 18 4. BLOWER MOTOR SPEED WIRING Figure Static CMA1-50Speed Tap \ PressureStatic CMA2-75Speed Tap \ Pressure5. FIELD WIRING AND REPLACING WIRING V.STARTING THE UNIT A. SEQUENCE OF OPERATIONS MAIN BURNER OPERATION CALL FOR HEAT SATISFIED B.INITIAL START UP OPERATING INSTRUCTIONSC.ADJUSTMENT OF BTU INPUT RATE GAS PRESSURE CHART FOR CMA* MODEL FURNACES D.BURNER ADJUSTMENTE.SETTING TEMPERATURE RISE FigureF.FURNACE CHECKOUT PROCEDURE VI. INSTALLERS INSTRUCTIONS TO USER VII. DEALER MAINTENANCEA.ELECTRICAL 2.CONDENSATE LINE/TRAP ASSEMBLY4. INDUCER BLOWER ASSEMBLY B.GENERAL INSPECTIONC.HEAT EXCHANGER 1.CLEANING THE COIL AIR SIDE5. GASKETS/SEALING MATERIALS D.HOUSE AIR BLOWERVIII. TROUBLESHOOTING FILTER MAINTENANCE PROCEDUREFILTER REPLACEMENT DIAGNOSTIC FEATURESThe LED will also flash once at power-up TROUBLESHOOTING GUIDE AT THE INTEGRATED CONTROL? Yes AFTER GAS VALVE OPENS, DO THE BURNERS IGNITE? DOES SYSTEM RUN UNTIL THERMOSTAT IS SATISFIED? IF LED LIGHT FLASHES APPENDIX – A REPLACEMENT PARTS Page APPENDIX – B WIRING DIAGRAM