Thermo Products CDX3-100N, CDX3-75N K. FILTERS 1. CHX3 MODELS HIGHBOYS, CDX3 MODELS COUNTERFLOWS

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K. FILTERS

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

K. FILTERS

1. CHX3 MODELS: HIGHBOYS

It is necessary to cut the return air opening in the bottom or side casing depending upon the needs of the specific installation.

NOTICE: If your CHX3 will require air delivery above 1800 CFM, it is advisable that both sides, a combination of 1 side and the bottom, or the bottom only be used for return air. (If a return is cut in the bottom, it should be as large as the return opening in the equivalent CDX3 model. (See specification sheet in beginning of this manual).

This CHX3 furnace has been factory supplied with a high quality re-usable filter rated for air velocities up to 600 ft/min. An optional Thermo Products filter rack assembly (part no. AOPS7547 for CHX3-75 thru 100 and AOPS7375 for CHX3-125) is available which is sized for the filter provided.

If an optional Thermo Pride filter rack AOPS7547 (figure 19) is used with the furnace, it will serve as a template to scribe a mark for the return air opening on the casing. Place the filter rack on the casing one inch up from the bottom of the furnace and centered from side to side. Place the securing flange against the casing for locating the return air opening.

Figure 19

PLEASE NOTE: While scribing the return air opening, the filter rack can be held into position by tape or similar means.

Position the open end of the filter rack so that it is accessible for filter replacement. Once the filter rack is positioned correctly, scribe a line along the inside of the securing flange of the filter rack on three of the sides. To scribe a line on the fourth side, on the open end, use the open end support for a guide.

Remove the filter rack and cut the return air opening in the casing. Now the filter rack can be permanently attached to the furnace with screws or pop-rivets along the securing flange.

Connect the return plenum to the filter rack and slide the filter into place.

2. CDX3 MODELS: COUNTERFLOWS

This CDX3 furnace has been factory supplied with two high quality reusable filters rated at 600 ft/min. These filters are designed to be mounted on the return air plenum opening on the top of the furnace in the double “vee” style rack provided (see Figure 20). If feasible, it is recommended that slits be cut in the return front to allow for easier access of the filters.

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Contents TWO STAGE CONDENSING GAS FURNACE MODELSOR LP GAS PROPANE CDX3-75N CDX3-100N CDX3-125N I. 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 CHX3 SERIES CDX3 SERIES INSTALLATION PARTS PACKAGES - CHX3-75 INSTALLATION PARTS PACKAGES - CDX3-75 Grounding instructions III. GENERAL INSTALLATION B1. CDX3 HORIZONTAL APPLICATION B. FURNACE LOCATIONPage PVC Pipe Designation Maximum Quantity of Elbows Outside Combustion Air Intake RH view E.Direct Venting Through a Sidewallc.The vent terminal shall not be located 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 Page Applications Furnace Model Series CHX3 Figure 9 Typical Internal VentPiping Arrangement for the 3. Connecting The Combustion Air Intake Piping Figure 14. TRAP ASSEMBLY MOUNTED ON CHX3 I.CONDENSATE DRAIN LINE AND TRAP ASSEMBLYFigure 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 HIGHBOYSPage L. WIRING Table 4A Time S7 DIP SwitchSwitch Settings Options2-StageBlower Settings from factory Table 4C IV. STARTING THE UNIT A. SEQUENCE OF OPERATIONS IF NOT IF THERMOSTAT W2 CONTACTS ARE CLOSED OTHERWISE OPERATING INSTRUCTIONS B. INITIAL START UPB.Gas flowrate by clocking gas meter C. Measuring And Adjusting Heat Input RateObserve the following precautions when measuring A.Burner manifold pressure with a pressure gaugeNOTICE 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 = Page Checking The Burner Flame 21.Go to Checkout Procedure belowCheckout Procedure TABLE 6 - CONVERTING GAS FLOW RATE V. INSTALLERS INSTRUCTIONS TO USER D. FURNACE CHECKOUT PROCEDUREFigure VI. TROUBLESHOOTING Power must be disconnected before servicing DIAGNOSTIC FEATURESTROUBLESHOOTING GUIDE IS INDUCER RUNNING ON LOW SPEED? YES DOES THE HOT DO BURNERS STAY LIT PAST PROOF OF FLAME CHECK? REPLACE THE 50V51-843CONTROL DOESBURNERSHUT OFF Appendix -AReplacement Parts List Page Page Page Appendix - B Wiring Diagrams
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