Thermo Products 125n, chx-3 75n, 100n IF THERMOSTAT W2 CONTACTS ARE CLOSED OTHERWISE

Page 44

IF THERMOSTAT

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

IF THERMOSTAT

W2 CONTACTS

ARE CLOSED

OTHERWISE

AFTER DELAY-TO-FAN-ON PERIOD ENDS (45 SECONDS), CIRCULATING AIR FAN IS ENERGIZED AT LOW FIRE HEATING SPEED OR HIGH FIRE IF W2 IS ENERGIZED. THE (OPTIONAL) ELECTRONIC AIR CLEANER AND HUMIDIFIER

ARE ENERGIZED.

IF SYSTEM IS IN LOCKOUT,

THE MODULE WILL RESET

ITSELF AFTER 60 MINUTES

OR MAY BE MANUALLY

RESET BY INTERRUPTING

THE POWER TO THE FURNACE

AT THE DISCONNECT OR

INTERRUPTING THE CALL FOR

HEAT AT THE THERMOSTAT.

IF THIS DOES NOT RESTART

THE SYSTEM, REFER TO THE

TROUBLESHOOTING SECTION

OF THIS MANUAL.

		THERMOSTAT CLOSES W2
		CALLING FOR HIGH FIRE
CALL		CALLING FOR HIGH FIRE
CALL		HEATING.
FOR		HEATING.
FOR
HIGH
FIRE

NO CALL

FOR

HIGH FIRE

WHEN THERMOSTAT W1 IS SATISFIED, CONTACTS OPEN AND THE GAS VALVE IS DE-ENERGIZED. AFTER PROOF OF FLAME LOSS, INDUCER STARTS 5 SECOND POST PURGE AND (OPTIONAL) HUMIDIFIER IS DE-ENERGIZED. THE DELAY-TO- FAN-OFF PERIOD BEGINS (120 SECONDS)

AFTER THE DELAY-TO-FAN-OFF PERIOD ENDS, THE CIRCULATING AIR FAN AND (OPTIONAL) ELECTRONIC AIR CLEANER ARE DE-ENERGIZED.

GAS VALVE, INDUCER AND AIR FAN ARE ENERGIZED TO HIGH FIRE SETTINGS

WHEN THERMOSTAT HAS SATISFIED W2, CONTACTS OPEN AND THE GAS VALVE AND AIR FAN HIGH FIRE SETTINGS ARE DE-ENERGIZED AFTER 30 SECOND DELAY.

38

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Contents MODELS FOR USE WITH NATURAL GAS OR LP GAS PROPANE CHX3-75N CDX3-75N CHX3-100N CDX3-100NCHX3-125N CDX3-125N INSTALLATION AND OPERATION MANUALI. SAFETY INFORMATION This and the previous page contain reproductions of the various warning and instruction labels placed on the Thermo Pride Two Stage Condensing Gas Furnaces. Please read and comply with the contents of these labels 1.A windows be opened The CHX3/CDX3 furnace models are sealed combustion design, which does not require an air shutter adjustment air shutters are not used for proper flame characteristics. Burner box access cover must always be secured with all screws in place and tightened before operating furnace BEGINNING PAGE INDEXSECTION II. FURNACE SPECIFICATIONS CDX3 SERIES INSTALLATION PARTS PACKAGES – CHX3-75 INSTALLATION PARTS PACKAGES – CDX3-75 Grounding instructions III. GENERAL INSTALLATION B. FURNACE LOCATION B1. CDX3 HORIZONTAL APPLICATIONFigure PVC Pipe Designation Maximum Quantity of Elbows E.Direct Venting Through a Sidewall Outside Combustion Air Intake RH viewc.The vent terminal shall not be located •near soffit vents, crawl space vents, or other areas where condensate or water vapor could create a nuisance, hazard, or cause property damage, and Page E1. Single-PipeSidewall Venting Option 5.Optional Direct Vent Terminations Install these optional kits according to the instructions provided with each kit. The location and clearance requirements are identical to those of the standard vent terminations described in this manual 1.Figures 6B, 7, and 8 follow depicting typical exhaust vent and air intake connections for the furnace model series CHX3 and the CDX3, respectively, as well as a list of required parts to correctly install each system Applications Applications leading away from the furnace must be composed of 3-inchdiameter PVC pipe and pipe fittings only. Refer to item E in Figure 3. Connecting The Combustion Air Intake Piping I.CONDENSATE DRAIN LINE AND TRAP ASSEMBLY Figure 14. TRAP ASSEMBLY MOUNTED ON CHX3Figure 15. TRAP ASSEMBLY MOUNTED ON CDX3 2.Determine on which side of furnace the condensate disposal line is to be run NOTICE: On CHX3/CDX3’s this must be the same side as the flue outlet or bottom of unit. Attach the condensate trap to the furnace casing using the #8x3/4” sheet metal screws provided in the parts package. Pilot holes are provided on both sides of the casing for mounting J. GENERAL GAS PIPING J1. REQUIREMENTS AND SIZING OF DUCT WORK Figure 18A TABLE 2A 2. CDX3 MODELS: COUNTERFLOWS K. FILTERS 1. CHX3 MODELS: HIGHBOYSFigure Figure L. WIRING Table 4A S7 DIP Switch Switch SettingsOptions Time2-StageBlower Settings from factory Table 4C IV. STARTING THE UNIT A. SEQUENCE OF OPERATIONS FLAME MUST BE DETECTED IF THERMOSTAT W2 CONTACTS ARE CLOSED OTHERWISE B. INITIAL START UP OPERATING INSTRUCTIONSC. Measuring And Adjusting Heat Input Rate Observe the following precautions when measuringA.Burner manifold pressure with a pressure gauge B.Gas flowrate by clocking gas meterNOTICE: A U-tubemanometer, measuring pressure in inches of water column, is recommended for all gas pressure measurements. However, an aneroid pressure gauge, in good working condition, capable of reading pressure changes of 0.05 in. W.G., or less, that was recently calibrated within the last year, is a satisfactory alternate. These two 2 devices will be considered as equivalent and interchangeable. Either device is referred to below as a “pressure gauge” Heat input rate in BTUH = Figure 21.Go to Checkout Procedure below Checking The Burner FlameCheckout Procedure TABLE 6 - CONVERTING GAS FLOW RATE D. FURNACE CHECKOUT PROCEDURE V. INSTALLERS INSTRUCTIONS TO USERFigure VI. TROUBLESHOOTING DIAGNOSTIC FEATURES Power must be disconnected before servicingTROUBLESHOOTING GUIDE IS INDUCER RUNNING ON LOW SPEED? YES DOES THE HOT DO BURNERS STAY LIT PAST PROOF OF FLAME CHECK? REPLACE THE 50V51-843CONTROL CHECK FOR 24 VOLTS Appendix –AReplacement Parts List Page Page Page Appendix – B Wiring Diagrams