DFX, DBX Vent-Free Fireplace Systems Installation & Operating Instructions Models: DFX24C, DFX32C, DBX24C WARNINGS If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life. 334051 VFS DBX cover – Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. – WHAT TO DO IF YOU SMELL GAS • Do not try to light any appliance.
CONTENTS DFX & DBX Series Vent Free Fireplaces Thank you and congratulations on your purchase of a MHSC Fireplace. PLEASE READ THE INSTALLATION AND OPERATION INSTRUCTIONS BEFORE USING THE APPLIANCE! IMPORTANT: Read all instructions and warnings carefully before starting installation. Failure to follow these instructions may result in a possible fire hazard and will void the warranty.
IMPORTANT SAFETY INFORMATION DFX & DBX Series Vent Free Fireplaces OWNER Please leave these instructions with the appliance. Please retain these instructions for future reference. WARNING INSTALLER • Any change to this heater or its controls can be dangerous. • Improper installation or use of the heater can cause serious injury or death from fire, burns, explosion or carbon monoxide poisoning. • Do not allow fans to blow directly into the fireplace. Avoid any drafts that alter burner flame patterns.
IMPORTANT SAFETY INFORMATION DFX & DBX Series Vent Free Fireplaces 20. Input ratings are shown in BTU per hour and are for elevations up to 2,000 feet. For elevations above 2,000 feet, input ratings should be reduced 4 percent for each 1,000 feet above sea level. Refer to the National Fuel Gas Code. 21. The appliance and its appliance main gas valve must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of 1/2 psig (3.5 kPa). 22.
PRODUCT FEATURES DFX & DBX Series Vent Free Fireplaces Gas Specifications Input BTU/hr Model Fuel Control Max. Min. 24DFXNMC Nat. Manual 22,000 15,000 24DFXPMC LP Manual 22,000 17,000 24DFXNVC Nat. Millivolt 22,000 17,000 24DFXPVC LP Millivolt 22,000 17,000 32DFXNVC Nat. Millivolt 26,000 20,000 32DFXPVC LP Millivolt 26,000 20,000 DBX24NTC Nat.
FIREPLACE and FRAMING DIMENSIONS DFX & DBX Series Vent Free Fireplaces D L S Min. Rough Opening Depth R H 1/2” or 5/8” S P M O - Min. Rough Opening Width Q Min. Rough Opening Height J G N B E Figure 2 Fireplace and Framing Dimensions C I F A K Ref.
Preinstallation information DFX & DBX Series Vent Free Fireplaces the grate only. Do not pick the unit up by the burners. • Gloves are recommended when handling ceramic fiber logs to prevent skin irritation from loose fibers. Logs are fragile — handle with care. GETTING STARTED Make sure you have received all parts: Check your packing list to verify that all listed parts have been received.
COMBUSTION and VENTILATION AIR DFX & DBX Series Vent Free Fireplaces ADEQUATE COMBUSTION AND VENTILATION AIR This heater shall not be installed in a confined space or unusually tight construction unless provisions are provided for adequate combustion and ventilation air. The National Fuel Gas Code, (ANSI Z223.1/NFPA54), defines a confined space as a space whose volume is less than 50 cubic feet per 1,000 BTU per hour (4.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces Fireplace Location Carefully select the best location for installation of your unvented fireplace. The following factors should be taken into consideration. • Clearance to side wall, ceiling, woodwork and window or other combustibles. Refer to “Clearances” section on Page 10. Minimum clearances to combustibles must be maintained.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces Ensure that minimum clearances shown in Figures 5 and 6 are maintained. Left and right clearances are determined when facing the front of the firebox. Follow these instructions carefully to ensure safe installation. Failure to follow these requirements may create a fire hazard. Sidewall Clearances — The clearance from the inside of the appliance to any combustible adjacent wall should not be less than 9" for the DBX24C/DFX24C and DFX32C.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces If unit is to be “built in”, fireplace framing can be built before or after the appliance is set in place. BE SURE THAT ALL PACKING MATERIAL HAS BEEN REMOVED FROM THE UNDERSIDE OF THE UNIT PRIOR TO SETTING THE FIREBOX IN PLACE. Construct fireplace framing following Figure 2 on Page 6 for fireplace dimensions. The framing headers may rest directly on top of the firebox.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces SECURING HEATER TO FLOOR OR HEARTH Note: Clearance requirements as detailed in “Clearances and Height Requirements” section on Page 16 of this manual, must be met before securing the heater in place. To prevent movement, the heater must be secured to the floor or hearth. 1. 2. 3. 4. 5. Open the control access door and remove the screen. Remove carton containing the four-log set.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces WARNING NOTICE: A qualified gas appliance installer must connect the heater to the gas supply. Consult all local codes. Use new black iron or steel pipe. Internally tinned copper or copper tubing can be used per National Fuel Code, section 2.6.3, providing gas meets hydrogen sulfide limits, and where permitted by local codes.
FIREPLACE INSTALLATION DFX & DBX Series Vent Free Fireplaces When tightening the joint to the valve, hold the valve securely to prevent movement. Test all gas joints from the gas meter to the heater valve for leaks using a gas analyzer or soap and water solution after completing connection. DO NOT USE AN OPEN FLAME. Check the gas pressure with the appliance burning and the control set to HIGH. Do not use open flame to check for gas leaks.
ELECTRICAL INSTALLATION DFX & DBX Series Vent Free Fireplaces ODS Pilot On/Off Switch ODS Pilot Wall Switch Valve On/Off Switch Spade Terminal TH = 3 TP = 1 TP/TH = 2 Figure 15 Wiring Diagram FP2112 Switch WARNING Optional Wall Switch or Remote Receiver Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing. FP2112 wiring diagram 12/08 Connecting Optional Wall Switch 1.
ELECTRICAL INSTALLATION DFX & DBX Series Vent Free Fireplaces Connect Remote Receiver THESE INSTRUCTIONS SUPERCEDE THE SECTION ENTITLED “HEARTH MOUNT” IN THE Millivolt HAND-HELD REMOTE INSTRUCTIONS SUPPLIED WITH THE REMOTE. Figure 16 1. Remove bottom louvre door. 2. Connect the remote connectors located in the unit. 3. Stick Velcro• pads with self-adhesive backing to bottom of remote receiver and to floor of compartment behind access panel. 4. Attach remote receiver to firebox with Velcro• pads.
WARNING FINAL INSTALLATION Do not operate the unit without the screen frame panel and canopy installed. REMOVE SCREEN DFX & DBX Series Vent Free Fireplaces Canopy Fireplace Screen 1. Remove bottom louver. Figure 17 2. Removing fireplace screen frame panel by pushing screen frame panel up and out. Figure 17 NOTE: Fireplace screen must be removed to access log box and to install canopy. FP2513 Louvre Figure 17 Remove Fireplace Screen Panel FP2513 Screws remove screen INSTALL CANOPY 1.
LOG PLACEMENT DFX & DBX Series Vent Free Fireplaces CAUTION WARNING Before you begin — This unit is supplied with six (6) ceramic fiber logs. Do not handle these logs with your bare hands. Always wear gloves to prevent skin irritation from ceramic fibers. After handling the logs, wash your hands gently with soap and water to remove any traces of fibers. The positioning of the logs is critical to the safe and clean operation of this heater.
LOG PLACEMENT DFX & DBX Series Vent Free Fireplaces Rear Log #3 DFX32C Log placement Figure 20 1. Install front right log (#1) on two pins on right side of burner. 2. Install left front log (#2) on two pins on left side of burner. 3. Install back log (#3) on back of burner. 4. Install right middle log (#4) on two pins on burner. Rest right end of right middle log on the right front log. 5. Install left middle log (#5) on two pins on burner. Rest left end of left middle log on left front log.
FLAME APPEARANCE DFX & DBX Series Vent Free Fireplaces Flames from the pilot, front and rear burner should be visually checked as soon as the heater is installed. In addition, periodically check the flames visually during operation. Check the pilot flame The pilot flame must always be present when the heater is in operation. It should just touch the top of the thermocouple tip for natural. Refer to Figures 23 & 24 for correct pilot flame.
DFX & DBX Series Vent Free Fireplaces FLAME APPEARANCE Checking burner flame DFX24C and DFX32C models In normal operation at full rate after 15 minutes, the following flame appearances should be observed: Burner will have a random pattern of yellow flames. Figures 25 and 26. There should be glowing embers in front of burner. DBX24C model In normal operation at full rate after 15 minutes, the following flame appearances should be observed: The flames inside the one-piece log may be yellow.
OPERATING INSTRUCTIONS DFX & DBX Series Vent Free Fireplaces WARNING for your safety read before lightinG If you do not follow these instruction exactly, a fire or explosion may result causing property damage, personal injury or loss of life. A. This appliance is equipped with a piezo ignition device which automatically lights the pilot. If piezo is not working properly, refer to Match Lighting Instructions, Page 33. B. BEFORE OPERATING smell all around the appliance area for gas.
OPERATING INSTRUCTIONS DFX & DBX Series Vent Free Fireplaces MANUAL control lighting instructions WARNING 1. STOP! Read the safety information. 2. Make sure the manual shutoff valve is fully open. 3. This heater is equipped with an ignition device (piezo) which automatically Rotate lights the pilot. 4. Refer to Page 22, Figure 23 for the location of the piezo ignitor and control knob. Push in gas control knob slightly and turn control knob clockwise to the OFF position.
DFX & DBX Series Vent Free Fireplaces OPERATING INSTRUCTIONS thermostatIC control lighting instructions 1. 2. 3. 4. 5. 6. 7. 8. 9. STOP! Read the safety information . Make sure the manual shutoff valve is fully open. This heater is equipped with an ignition device (piezo) which automatically lights the pilot. Refer to Page 22, Figure 28 for the location of the piezo ignitor and control knob. Turn control knob clockwise to the OFF position. Wait 5 minutes to clear out any gas.
DFX & DBX Series Vent Free Fireplaces OPERATING INSTRUCTIONS Millivolt control lighting instructions 1. STOP! Read the safety information label. 2. Make sure the manual shutoff valve is fully open. 3. This gas log set is equipped with an ignition device (piezo) which automatically lights the pilot. If piezo ignitor does not light the pilot, refer to instructions for Match Lighting Instructions, Page 26. 4.
DFX & DBX Series Vent Free Fireplaces OPERATING INSTRUCTIONS and MAINTENANCE MATCH lighting instructions 1. Remove any items necessary for easy access to the pilot (for example: logs, screens, etc.). 2. Follow appropriate lighting instructions found previously. Instead of pushing and releasing the piezo button, light a match and hold the flame to the end of the pilot and ignite the pilot. 3. After control knob has been released and pilot stays lit, reinstall any items that were removed for pilot access.
WARNING TROUBLESHOOTING DFX & DBX Series Vent Free Fireplaces If the gas quality is bad, your pilot may not stay lit, the burners may produce soot and the heater may backfire when lit. If the gas quality or pressure is low, contact your local gas supplier immediately. REMEDY OBSERVED PROBLEM POSSIBLE CAUSE ODS/pilot lights, but flame goes out when control knob is released. 1. Control knob not fully pressed in. 2. Control knob not pressed in long enough. 3. Manual shutoff valve not fully open. 4.
REPLACEMENT PARTS DFX & DBX Series Vent Free Fireplaces 1 3 4 5 2 6 DFXC/DBXC Firebox Parts Description Canopy Screen Assy. Left Firebrick (Optional) Center Firebirck (Optional) Right Firebrick (Optional) Blower (Optional) WARNING Ref. 1. 2. 3. 4. 5. 6. 28 334051 Qty.
REPLACEMENT PARTS DFX & DBX Series Vent Free Fireplaces 1 3 14 16 15 5 2 4 7 10 13 9 13 10 10 8 12 11 6 5 DFX24C Millivolt & Manual Control Burner Parts Ref. 1. 2. 3. 4. 5. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. DFX24C Millivolt DFX24C Manual Description Qty. Natural Propane Natural Propane Burner/Grate Assy.
REPLACEMENT PARTS DFX & DBX Series Vent Free Fireplaces 14 1 3 15 16 10 11 2 9 4 4 7 9 13 12 8 10 6 5 DFX32C Millivolt Burner Parts DFX32C Millivolt Description Qty. Natural Propane Burner/Grate Assy. 1 33D5050 33D5050 Injector 1 33D5040 33D5039 Venturi 1 58D0454 33D4058 334051 1 ODS Pilot Assy.
REPLACEMENT PARTS 2 DFX & DBX Series Vent Free Fireplaces 8 1 9 7 10 3 4 6 5 DBX24C T-STAT Burner Parts Ref. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. DBX24C T-Stat Description Qty. Natural Propane Burner 1 33D0070 33D0071 Injector 1 18D0523 33D0281 ODS Pilot Valve Tube, 3/16 1 49D0050 49D0050 334051 ODS Pilot Assy.
DFX & DBX Series Vent Free Fireplaces OPTIONAL ACCESSORIES Forced Air Kit If you are installing the forced air kit (Models BLO24-T, BLO24-TB or BLOT), see the installation instructions provided with the kit for electrical wiring requirements or the blower installation section. Model DFX24C uses blower model BLO24T. Model DFX32C uses blower model BLOT. Model DBX24C uses blower model BLO24TB. The firebox must be connected to main power supply at time of firebox installation.
OPTIONAL ACCESSORIES DFX & DBX Series Vent Free Fireplaces installing optional FIREbrick panels Hole 1. Remove optional firebrick panels from packaging. Check that you have the following: • 3 firebrick panels • two (2) retainer brackets • two (2) black screws 2. 3. 4. 5. 6. Retainer Clip If any part or parts are missing, contact dealer where you bought fireplace. Turn off fireplace and allow to cool. Remove fireplace screen, Page 17, Figure 17 and logs.
OPTIONAL ACCESSORIES DFX & DBX Series Vent Free Fireplaces 3. Use one 90° angle trim bracket to join the corner of one piece of side trim to the corner of the top trim piece. Figure 38. A rubber hammer or handle of a claw hammer will help secure the corners. 4. Repeat for other side. NOTE: If you do not attach the trim at the correct corners, use a hammer and screwdriver to tap on the one end of the 90° angle bracket. This will separate the two pieces of trim. Figure 39 5.
OPTIONAL ACCESSORIES DFX & DBX Series Vent Free Fireplaces Assembled Trim Trim Flush with Front of Fireplace Figure 42 Slide Assembled Trim Over Top of Heater FP2527 FP2527 install trim Screws Screw Holes Screw Figure 43 Secure Trim to Fireplace FP2528 33D4047 35 FP2528 secure trim
LIMITED LIFETIME WARRANTY POLICY Lifetime Warranty The following components are warranted for life to the original owner, subject to proof of purchase: Firebox, Combustion Chamber, Heat Exchanger, Grate and Stainless Steel Burners. Five Year Warranty The following components are warranted for 5 years to the original owner, subject of proof of purchase: Ceramic Fiber Logs, Catalytic Filter and Aluminized Burners.