Boiler Manual - Weil-McLain

GV90+ gas-fired water boiler — Boiler ManualDIRECT VENT — Sidewall with 3” concentric (continued)Install termination — concentric pipes1. Assemble the vent termination as described for concentric terminations,on page 47.If necessary, you can shorten the lengths of the inner andouter pipes for a shorter finished assembly. But you mustensure the pipes butt correctly at both ends. Failure toproperly assemble the concentric termination can resultin flue gas recirculation, causing possible severe personalinjury or death.2. Wall penetration:a. Preferably, use a thimble with a 4½-inch hole. If not using athimble, carefully use a hole saw to cut a hole not larger than4¾ inches in diameter through the wall. The finished holemust provide a solid stop for the rain cap ribs, as shown in theinset to Figure 52.3. Secure the termination in place so the rain cap will butt against theoutside wall or outer thimble plate as shown in Figure 52, page 42.4. Before beginning vent and air piping from the boiler to the concentrictermination, mount and secure the concentric terminationas shown in Figure 52, page 42.The vent and air piping must be securely supported, andmust not rest its weight on the boiler fittings. Failure toproperly support the vent and air piping could result invent piping damage, resulting in possible severe personalinjury, death or substantial property damage.Figure 51 Termination location — concentrictermination — multiple boilers —clearance from vent of one to air intake ofthe nextFigure 52 Installing and supporting the concentricsidewall vent assemblyThe supports/bracing used must support the terminationassembly to prevent slippage or movement.The clamps used on the outside of the termination pipemust not cut into the pipe or contain sharp edges thatcould cause a crack to form.When inserting the partially-assembled terminationkit through the wall penetration, wrap plastic or otherprotection over the end of the exposed assembly to preventdebris from entering the pipes. If the air passagesbecome blocked, the boiler will not operate. Once therain cap has been cemented to the assembly, there is noway to correct the problem. The assembly would haveto be replaced if it were cut to be removed and cleaned.Altering the assembly in any way could result in severepersonal injury or death due to toxic flue product emissions.When using AL294C stainless vent pipe, use the ventpipe manufacturer’s PVC adapter when connecting tothe concentric vent attachment.5. After the assembly has been positioned in the opening and all supportshave been attached, install a bird screen (purchased separatelyif not included with the kit) and rain cap as follows:a. Place the bird screen on the end of the inner pipe as in Figure58, page 47.b. Cement the rain cap in place as shown.Ensure that the wall material is strongenough to prevent the rain cap from beingpushed inward if struck or pushed from theoutside.42Part number 550-142-054/1211