Thermo Products CMA1-50N, CMA2-75N service manual Troubleshooting Guide

Page 47

TROUBLESHOOTING GUIDE

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

TROUBLESHOOTING GUIDE

THE SYSTEM IS STARTED BY SETTING THE THERMOSTAT TO CALL FOR

HEAT. THE FOLLOWING SHOULD HELP ESTABLISH THE TYPE OF MALFUNCTION OR DEVIATION FROM THE NORMAL OPERATION.

TO USE THIS DIAGRAM, YOU JUST NEED TO FOLLOW THE INSTRUCTIONS IN THE BOXES.

NOTE: CHECK DIAGNOSTIC CODE THROUGH VIEW PORT PRIOR TO REMOVING ACCESS DOOR.

TURN THERMOSTAT TO CALL FOR HEAT
DOES THERMOSTAT MAKE CONTACT?	No
	No


				No					No
		IS ROOM TEMPERATURE				IS ROOM


Yes		BELOW THERMOSTAT				TEMPERATURE
Yes		BELOW THERMOSTAT				TEMPERATURE
		SETTING?			ABOVE 90 DEGREES F?

			Yes				Yes
							Yes

TURN T'STAT

SETTING ABOVE

ROOM TEMP.

IS THE TRANSFORMER

SUPPLYING 24 VOLTS

TO THE THERMOSTAT?

Yes

REPLACE

THERMOSTAT

Yes

COOL THE THERMOSTAT

No
ARE WIRES CONNECTED	No
ARE WIRES CONNECTED
PROPERLY?
Yes
IS INTERNAL DAMAGE	No
IS INTERNAL DAMAGE
PRESENT ON THE
TRANSFORMER?

Yes

REPLACE TRANSFORMER

CORRECT WIRE CONNECTIONS

CHECK INPUT POWER, DOOR INTERLOCK, SERVICE SWITCH AND FUSES.

IS THE INDUCER

BLOWER OPERATING?

Yes

No

IS THERE 24 VOLTS ACROSS "TH" & "TR"

AT THE INTEGRATED CONTROL MODEL?

Yes

No

CHECK FOR CONTINUITY

&PROPER CONNECTIONS

45

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Contents DOWN FLOW & DIRECT VENT SEALED COMBUSTION INSTALLATION AND SERVICE MANUALFOR YOUR SAFETY GAS FIRED HIGH EFFICIENCY FURNACESECTION TABLE OF CONTENTSI. 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 GAS SUPPLY PRESSURE II. FURNACE SPECIFICATIONS - CMA SERIESDIMENSIONS MODELINSTALLATION PARTS PACKAGE NON-COMBUSTIBLEMATERIAL COMBUSTIBLE MATERIAL.” COMBUSTIBLE MATERIALTable IV. GENERAL INSTALLATION A.FURNACE LOCATIONMODELS CMA Figure 1B Combustible Floor Base Model: 70-BASE Figure 1ACoil Cabinet Cottage Base Model: 01COT-BASE Figure 1C Figure Figure B. BASE INSTALLATION1. Combustible Floor Base Model: 70 BASE Figure C. ALCOVE INSTALLATION2. Cottage Base Model: 01COT BASE Figure D. CLOSET INSTALLATIONE. FUEL PIPING F.GENERAL VENTING REQUIREMENTS Table MAXIMUM VENT LENGTHFigure 6. CMA*-75SHOWN 1. Vent And Combustion Air Pipes H. Direct Venting Through a Sidewall2. Exhaust Vent Termination Elbow Sidewall Venting Page 4. Vent Terminal Location Guidelines Terminations Figure Figure 5.Secure plate to roofFigure K.CONDENSATE DRAIN LINE AND TRAP ASSEMBLY 1. Electrical Branch Supply Circuit Figure L.ELECTRICAL WIRING2.Connection Of Power Supply Wires 3.Connection Of Room Thermostat WiresElectrical Wire Diameter AWG 24 22 20 18 4. BLOWER MOTOR SPEED WIRING Figure Pressure CMA1-50Speed Tap \ StaticPressure CMA2-75Speed Tap \ Static5. FIELD WIRING AND REPLACING WIRING V.STARTING THE UNIT A. SEQUENCE OF OPERATIONS MAIN BURNER OPERATION CALL FOR HEAT SATISFIED OPERATING INSTRUCTIONS B.INITIAL START UPC.ADJUSTMENT OF BTU INPUT RATE D.BURNER ADJUSTMENT GAS PRESSURE CHART FOR CMA* MODEL FURNACESFigure E.SETTING TEMPERATURE RISEF.FURNACE CHECKOUT PROCEDURE VII. DEALER MAINTENANCE VI. INSTALLERS INSTRUCTIONS TO USERB.GENERAL INSPECTION 2.CONDENSATE LINE/TRAP ASSEMBLY4. INDUCER BLOWER ASSEMBLY A.ELECTRICALD.HOUSE AIR BLOWER 1.CLEANING THE COIL AIR SIDE5. GASKETS/SEALING MATERIALS C.HEAT EXCHANGERDIAGNOSTIC FEATURES FILTER MAINTENANCE PROCEDUREFILTER REPLACEMENT VIII. TROUBLESHOOTINGThe 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