424WBST Designer Woodburning Fireplace Homeowner's Installation and Operating Manual 342 COVER For use in U.S./Canada Underwriter's Laboratories Report No. MH7603 DO NOT DISCARD THIS MANUAL: Retain for future use. 87D1506 12/09 Rev.
424WBST Designer Woodburning Fireplaces Safety Information Please read this manual before installing and using FIREPLACE. 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. Description The 424WBST fireplaces are multi-side solid fuel, woodburning fireplaces. These are radiant models only and include a preinstalled outside air kit.
424WBST Designer Woodburning Fireplaces 424WBST Fireplace Dimensions 11” (279 mm ) Dia. 8” (203 mm ) Dia. 12" (305 mm) 24" Total Unit Width CL Framing Width Will be 24" Minus 2 x (Drywall Thickness) 20” (508 mm) 1856M” (464 mm) 52 6M” (1340 mm) 36" (914 mm) 12” (305 mm) 756O” (191 mm) 37” (940 mm) 49(6 ” (1267 mm) 21” (533 mm) 29 6QE” (741 mm) 14 6 ” (372 mm) 956O” (241 mm) 12” (305 mm) 756O” (191 mm) 36” (914 mm) Outside Air 40” (1016 mm) Gas Line Access Fig.
24WBST Designer Woodburning Fireplaces 424WBST Woodburning Fireplace Flue Collar Outer Collar Header Standoffs Ledge Brackets Outer Dome Flue Damper Control (Inside) Brick liner on Sides and Hearth Gas Line Knock-out (Both Sides) Gas Line Access Wood Grate Hearth Firebox Outside Air Access Air Inlet Outside Air Control Metal Safety Strips, shown not in place (1, 2, or 3 Pieces) FP701a Fig. 3 424WBST Parts Identification.
424WBST Designer Woodburning Fireplaces Chase Installation Insulation methods shown are optional for cold climate, not a requirement for unit operation. Termination Cap Storm Collar Pan Flashing Batt Insulation (cut out around firestop) Firestop Draftstop Ceiling Level Outer Dome Refer to Figures 21 and 26 for clearance information.
424WBST Designer Woodburning Fireplaces Chimney Requirements - Offset Installations OFFSET CHIMNEY FLUE EXIT RISE CHIMNEY SECTION B A D E 6 FT. C G 30˚ OFFSET ELBOW RISE H OFFSET 30˚ RETURN ELBOW 30˚ OFFSET ELBOW B FP282 30˚ RETURN ELBOW 30° Elbow Offsets G 1' 1¹⁄₂' 3' 4' SKCS8 SUPPORT H HEARTH FLOOR Example 1 Example 2 Notes: G + H cannot exceed 20 feet.
424WBST Designer Woodburning Fireplaces Planning Information Preplanning an installation is very important to ensure safety and to save time and money. An installer must predetermine where a fireplace will be set and how the chimney system will be run. NOTE: The 424WBST model uses MHSC SK8 (2-wall) chimney systems. Mounting the Fireplace A fireplace may only be mounted on the following surfaces: 1. A flat combustible surface. 2. A raised wooden platform. 3.
424WBST Designer Woodburning Fireplaces Installation Chimney Supports The chimney system is supported by the fireplace for vertical chimney heights less than 20' (6 m) above the hearth. Chimney supports are required if the vertical height exceeds 20' (6 m). Locate chimney supports at ceiling holes or other structural framing at 20' (6 m) heights. Spacing between chimney supports must not exceed 20' (6 m). Use Chimney Support Model SKCS8 for SK8 chimney.
424WBST Designer Woodburning Fireplaces Chimney Set-up Framing Framing can be constructed before or after the fireplace is set in place, however, most installers build the frame before setting the fireplace. Frame fireplace with 2 x 4 lumber or heavier materials. Refer to framing dimensions in Figures 1, 2, 3 or 4 for basic fireplace specifications. Headers and support studs must be turned on end as illustrated on Page 5, Figure 4.
424WBST Designer Woodburning Fireplaces Framing the Ceiling Hole Actual Centerpoint 2056O” (521 mm) Chimney Centerline Frame the ceiling chimney hole as shown in Figure 12. It is good practice to use framing lumber that is the same size as the ceiling joists; this is a requirement at attic level.
424WBST Designer Woodburning Fireplaces Positioning, Safety Strips, Securing the Fireplace Slide fireplace into position. Lift the fireplace front slightly and slide the metal safety strips under front bottom edge about 1¹⁄₂" (38 mm), allowing the remainder to extend in front of firebox. Overlap strips at least 1/2" (13 mm) to provide a positive joint. (Flat safety strips are packed with fireplace.) (Fig.
424WBST Designer Woodburning Fireplaces Installing the Chimney System Pipe Section Start by attaching the first chimney section to the collar on top of the fireplace. Pipe Rim UP Install the pipe as pictured in Figure 16. When you get a good lock, you will hear the pipe clearly snap together. Once sections are snap-locked in place, it is extremely difficult to get them apart. Make sure the pipe is firmly snapped and locked together as each pipe section is mounted.
424WBST Designer Woodburning Fireplaces Firestop spacers are not available for nor are they required on vertical walls. Consider this dimension when determining how many straight chimney sections are needed. DO NOT put any sealant around the area where the outer pipe slides through the firestop spacer. If you seal this area, it may cause a fire hazard. Note: Chimney supports are generally used in long runs in a chase installation. A chimney support cannot be mounted directly to the fireplace.
424WBST Designer Woodburning Fireplaces Install Remainder of Chimney Sections Air Space Clearances Since you have already preplanned the height of your termination according to the Ten Foot Rule, continue to install pipe to the predetermined height. Check the chimney top installation instructions for details on how high above the roof top the chimney sections (all pipes) should extend. Combustible framing material MUST NOT penetrate AIR SPACE (shaded areas).
424WBST Designer Woodburning Fireplaces Mantel Clearance No Noncombustible Facing Material 1/2" Noncombustible Material Header Ledge Bracket * Standoff 1/2" 2 x 4 Stud 12" (305mm) Min. Finished Wall 12" (305mm) Max. Finished Wall Combustible Mantel and Trim Standoff 12" (305mm) Max. Combustible Mantel and Trim Mantel Clearance with Noncombustible Facing Material 2 x 4 Stud 12" (305mm) Min. Noncombustible Material Header Ledge Bracket 6“ (159mm) Min.
424WBST Designer Woodburning Fireplaces Side Wall Protection Examples of wall shield insulation: All joints (top, bottom and sides) where wall or decorative facing material meets fireplace surround must be completely sealed with a noncombustible material. (Figs. 20 and 24) 1. Manville - CERAFORM 126, K=.27, 1/2 inches thick 2. MHSC - EH2416, K = .458, 1 inch thick required.
424WBST Designer Woodburning Fireplaces Minimum Hearth Extension Dimensions Minimum Wall Clearances WITH Noncombustible Surround Facing (for On-Site Construction) WITHOUT Noncombustible Surround Facing Shaded area starts 1/2" away from edge of unit 4" 4" BRICK (Example material) E F** C** Side Wall Firebox Opening E G G J D A - Min. clearance to combustible perpendicular wall May install noncombustible decorative covering OR .018" min. sheet metal Side B - Min.
424WBST Designer Woodburning Fireplaces Example of Determining Hearth Extension Equivalents To determine the thickness required for any new material: NEW K of new material (per inch) thickness required = X of listed thickness K of listed material (per inch) material Seal Cracks Between Fireplace and Hearth Extension with Noncombustible Material Noncombustible Material 7Z\x" Max.
424WBST Designer Woodburning Fireplaces Installing Line for Gas Logs Monessen Fireplaces are designed to accept a 1/2" (13 mm) gas line for installation of an approved gas appliance. (MHSC manufactures a wide variety of gas logs for use in Monessen fireplaces.) Be sure to have the appliance installed in accordance with building codes. Fireplace Top View Hole in Outer Casing 1" Gas Line Tube Supply Line Repack Insulation Gas connection may enter from either left or right side of the fireplace.
424WBST Designer Woodburning Fireplaces 1, 2, 3 4 d c 5 7 b 8 a 6 9 11 10 12 961 MHSC reserves the right to make changes in design, materials, specifications, prices and discontinue colors and products at any time, without notice. 424WBST Woodburning Fireplace Ref. 1. 2. 3. 4. 5. 6. 7a. 7b. 7c. 7d. 8. 9. 10. 11. 12.
424WBST Designer Woodburning Fireplaces Accessories The following accessories for this appliance are available from your local Monessen distributor. Should you need additional information beyond what your distributor can furnish, contact: MHSC, 149 Cleveland Drive, Paris, KY 40361, Attn: Technical Services. CAUTION: This fireplace and chimney assembly is a highly engineered system, and, as such, must be operated only with MHSC approved components.
424WBST Designer Woodburning Fireplaces Chimney Components U.S. Component Description Model Number Round Top Termination Round termination to be used with SK8 chimney RLTSK8 system. (Flashing not included.) Long Round Top Round top to be used with a chase installation RLTSK8L Termination utilizing SK8 chimneysystem. Knock-down Shroud Black pyramid knock-down shroud used for PKDSBL Pyramid chase installations with any RLT round top termination. Gives appearance of a pyramid cap.
424WBST Designer Woodburning Fireplaces Canada Component Description Model Number Attic Insulation Shield Used to prevent insulation from coming in AIS-SK - SK8 contact with the chimney system. SK8 Chimney Sections Used to build chimney systems exposed above SK818CAN (1¹⁄₂') SK8 roof. SK84CAN (4') SK8 45° Chimney Elbows Provides 45° offset and return. For Canadian SK845/2 installations only. For use with SK8 chimney only. (Maximum use of 2, or 1pair.
LIMITED WARRANTY Factory-Build Fireplace and Components (Except Blowers) What is Covered and For How Long Five-Year Coverage: For five years from the date this fireplace and components are first purchased for use, MHSC will, at its option, repair or replace any defective part of this fireplace or components, or refund to you a sum not to exceed the factory retail price in effect at the time of purchase.
