Pentair MT warranty 2C. Installation of Outdoor Units, 2B-2. Venting

MegaTherm Commercial Pool Heating Boiler Page 5

2B-2. Venting

1.Model MT boilers have built-in draft diverters for natural draft operation and must not be connected into any portion of a mechanical draft system under positive pressure. The flue outlet must be connected to a clear, unobstructed vent of adequate capacity terminating above the highest point of the building with an approved vent cap. The venting system should be installed according to the latest edition of ANSI Z223.1 (or CAN1-B149) and any local codes having jurisdiction.

IMPORTANT NOTE: Do not use sheet metal screws at the snap lock joints of Type B gas vents.

2.Do not weld or fasten the vent pipe to the boiler draft hood. The weight of the stack must not rest on the boiler. The draft hood and top must be easily removable for normal boiler service and inspection.

3.Avoid long horizontal runs of the vent pipe, and too many 90 degree elbows, reductions and restrictions. Horizontal runs should have at least a 1/4” rise per foot in the direction of flow. A vent connector shall be supported for the design and weight of the material employed to maintain clearances and prevent physical damage and separation of joints.

4.Avoid terminating boiler vents near air conditioning or air supply fans. The fans can pick up exhaust flue products from the boiler and return them inside the building, creating a possible health hazard. A minimum of 4 feet horizontal distance must be maintained from electric meters, gas meters, and relief equipment.

5.Always use double-wall or insulated vent pipe (Type B or equivalent). In cold weather, uninsulated outside vents can chill the rising flue products, blocking the natural draft action of the venting system. This can create a health hazard by spilling flue products into the boiler room.

6.Avoid oversize vent piping or extremely long runs of the pipe which may cause excessive cooling and condensation. Rule of Thumb: The total length of the vent, including the connector and any offset, should not exceed 15 feet for every inch of vent diameter. Longer total lengths shown in venting tables are based on maximum capacity, not condensation factors.

7.When the installation of a draft fan is necessary in the venting system to which a Model MT boiler is to be connected, the installation should be engineered by competent personnel following good engineering practices. The draft fan supplier should be consulted for correct size. The installation should be in accordance with the latest edition of ANSI Z223.1 and any local

codes having jurisdiction. When a draft fan is installed, a suitable draft switch must be used and wired into the boiler control circuit at terminal designated “Field Interlock,” to prevent firing of the unit unless a positive draft has been established (see Figure 3).

Figure 3. Draft Fan Wiring Diagram.

2C. Installation of Outdoor Units

1.Locate the boiler to provide the minimum clearances as listed in Section 2A, “Boiler Placement.”

2.Do not locate the boiler in an enclosure or wall recess. Avoid locations where wind deflection off structures might cause down draft. When such wind conditions are possible, locate the unit at least three (3) feet from the structures.

3.Never install the boiler under any kind of roof overhang. Do not locate the unit below or adjacent to any doors, windows, louvers, grills, etc. which communicate in any way with an inhabited area of a building. Even though such communication might be through another structure such as a garage or utility room (see Figure 4).

Figure 4. Incorrect Outdoor Installation.