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Model SFT Sizes 45, 60 and 75 are certified to CSA Requirement 10-96 for RESIDENTIAL INSTALLATION Gas-Fired, Separated-Combustion, Power-Vented Unit Heaters ® APPLIES TO: INSTALLATION FORM RZ-I-SFT Obsoletes Form RZ 432 (Version C) Installation/Operation/Service Models SFT 45, 60 and 75 are certified for both residential and commercial/industrial installations. Models SFT 100-300 are certified for commercial/industrial installations only. Table of Contents Installation and Operation .................
GENERAL (Cont'd) These separated combustion units are designed and manufactured in accordance with the ANSI definition of separated combustion.
. High Altitude Operation If the heater is being installed in an altitude above 2000 ft (610M), check the rating plate to determine what must be done to prepare the heater for high altitude operation. Check the rating plate, determine which circumstance below applies, and follow the instructions. • • If the altitude range on the rating plate agrees with the altitude at the site, no further action is required. Proceed with the installation.
WARNING: Unit must be level for proper operation. Do not place or add additional weight to the suspended heater. See Hazard Levels, page 2. C L Figure 2B - Two-point Suspension - Applies to Sizes 45, 60, and 75 only 16 ) 9/ mm 9 43 (2 Figure 2A - Four-point Suspension (applies to all sizes) Be sure that the threaded hanger rods are locked to the heater as illustrated. Recommended maximum hanger rod length is 6 feet (1829mm).
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9. Venting and Combustion Air All separated combustion, power vented units MUST BE equipped with both combustion air and exhaust piping to the outdoors. The unique concentric adapter assembly required with this heater allows for both combustion air and exhaust piping with only one horizontal or vertical penetration hole in the building. Installation should be done by a qualified agency in accordance with these instructions.
2. Type of Pipe (field-supplied) (cont'd) Combustion Air Inlet Pipe Between the Heater and the Concentric Adapter - Sealed, single-wall galvanized pipe is recommended. Combustion Air Pipe Between the Adapter Box and the Combustion Air Inlet - The vent pipe is internally concentric to the combustion air pipe; use single-wall galvanized pipe for the combustion air pipe. 3.
. Venting and Combustion Air (cont'd) Installation Requirements for Option CC6 (cont'd) Field-supplied installation requirements: • Thimble (a thimble is not required if wall is of non-combustible construction) • Flashing • Vent pipes (see requirements on pages 6-7) • Combustion air pipes (see requirements on page 7) • Mounting brackets for concentric adapter box (or box may be mounted flush, depending on building construction) • Taper-type reducers and/or enlargers as required (see requirements on page 7)
Position the vent pipe so that it will extend a minimum of 16" past the end of the combustion air pipe. See Figure 6A. If a reducer is required, a maximum of 6" (152mm) of vent pipe should extend out the heater side. Any time the pipe is re-positioned, re-check the seal to be sure that it has not rolled. Adjust the pipe and seal until the pipe is the correct length on each side of the box and the seal is over the edge of the hole and tight to the entire circumference of the pipe.
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3. Attach the concentric adapter. Insert the vent pipe and combustion air pipe up through the roof and secure the adapter box. Flash the combustion air pipe to the outside of the roof as required. 7B 22" (559mm) minimum 7C 7D Exhaust Terminal 12" (305mm) minimum Slide combustion air inlet over the vent pipe and fasten to the end of the combustion air pipe. 5. Attach the exhaust terminal with sheetmetal screws (See Figure 7D). 6.
9. Gas Piping and Pressures Immediately upstream of the gas supply connection, install a manual shutoff valve with a 1/8 NPT plugged tap accessible for test gauge connection. WARNING: This appliance is equipped for a maximum gas supply pressure of 1/2 pound, 8 ounces, or 14 inches water column. Supply pressure higher than 1/2 pound requires installation of an additional lockup-type service regulator external to the unit.
Instructions on How to Check Manifold Pressure (can only be done after heater is installed): 1) With the manual valve positioned to prevent flow to the main burners, connect a manometer to the 1/8" pipe outlet pressure tap in the valve. NOTE: A manometer (fluid-filled gauge) is recommended rather than a spring type gauge due to the difficulty of maintaining calibration of a spring type gauge. 2) Open the valve and operate the heater. Measure the gas pressure to the manifold.
14. Combustion Air Proving Switch The combustion air proving switch is a pressure sensitive switch that monitors air pressure to ensure that proper combustion air flow is available. The switch is single pole/double throw with the normally open contacts closing when a decreasing pressure is sensed in the system. On start-up when the heater is cold, the sensing pressure is at the most negative level, and as the heater and flue system warm up, the sensing pressure becomes less negative.
Typical Wiring Diagram L1 (HOT) L2 (COM) 115/1/60 BK (SEE NOTE 6) BK BK 1 1 BL FLAME ROLLOUT SWITCH LINE VAC HOT BL BL CMB BLWR AUX 24VAC HOT BL VENTER MOTOR GROUND BR FLAME SENSE OPT. SINGLE STAGE THERMOSTAT SET ANT. AT 0.
CHECK/TEST/START-UP 18. Check Installation and Start-Up Check the installation prior to start-up: Instructions Check suspension. Unit must be secure and level. 1. Set thermostat at lowest setting. Check clearances from combustibles. Requirements are shown in Paragraph 6. 2. Turn off all electric power to the appliance. Check vent/combustion air system to be sure that it is installed according to the instructions in Paragraph 9. Check piping for leaks and proper gas line pressure.
TO TURN OFF GAS TO THE APPLIANCE 1) Set thermostat to lowest setting 2) If service is to be performed, turn off all electric power to the appliance. 3) Open the access door. 4) Turn the gas control knob or lever clockwise to "OFF". Do not force. 5) Close the access door. Check installation after start-up: If the heater is being derated for high altitude operation (See Paragraph 5), follow the instructions in Paragraph 10 to adjust the manifold pressure.
SERVICE AND MAINTENANCE WARNING: Should overheating occur, or the gas supply fail to shut off, shut off the manual gas valve to the appliance before shutting off the electrical supply. WARNING: Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and replace any gas control which has been under water. WARNING: If you turn off the power supply, turn off the gas. See Hazard Levels, page 2.
21. Heat Exchanger 7. Remove the small manifold seal plate and cover plate. Remove the burner box cover. The burner rack assembly is visible. 8. At the bottom of the burner rack assembly, remove the nut that secures the burner rack to the bolt welded to the burner box bottom. At the top of the burner rack assembly, remove the bolt that attaches the burner rack assembly to the bracket. Lift the burner rack/ manifold assembly upward (to clear the locating weldpins) and pull the assembly out of the heater.
22. Ignition System (cont'd) 24. Venter Motor IMPORTANT: When re-assembling, the brown ground wire must remain attached to the ignitor. Remove dirt and grease from the motor housing. Power venter motor is permanently lubricated. The integrated ignition control module controls and monitors operation of the venter motor. If the contacts fail to close, the venter motor will not run. If the contacts fail to open, the venter motor will not shut off, preventing the combustion air pressure switch from opening.
25. Limit Controls If it is determined that a limit control needs replacing, use only the factory-authorized replacement part that is designed for the size of heater. To access the limit control on Sizes 45-75, remove the louver assembly from the front of the heater. On Sizes 100-300, the limit control is accessible in the control compartment. For approximate limit locations, see Figure 14 on page 19. 26.
30. Troubleshooting (cont'd) PROBLEM (cont'd) PROBABLE CAUS E (cont'd) Burners will not 8. Integrated ignition control module does not light (cont'd) power main valve. a) Loose wire connections b) Flame sensor grounded c) Incorrect gas pressure d) Cracked ceramic at sensor 9. Flame rollout switch open a) Air blockage through the unit b) Faulty flame rollout switch 1. Gas pressure too high or too low. REMEDY (cont'd) 8. a) Check and tighten all wiring connections.
31. Heater Rating Plate The heater rating plate is a quick reference for information about a heater and its installation requirements. In addition, the Serial No. on the rating plate identifies components used in manufacturing that specific heater. The serial number is coded to identify the gas valve and ignition type that was installed on the heater at the time of manufacture. This information is required if service and/or replacement parts are required.
FOR SERVICE OR REPAIR, FOLLOW THESE STEPS IN ORDER: FIRST: Contact the Installer Name ___________________________________________________________________________ Address ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ Phone ___________________________________________________________________________ SECOND: Contact the neares
