Bosch Appliances GWH-635-ES manual Clearances, Mounting installation, Combustion air requirements

Appliance details

2.6Clearances

The GWH-635-ES is design certified for installation on a combustible wall (see 2.7 Mounting installation) provided the floor covering below the heater is noncombustible. For installations in an alcove or closet, maintain the minimum clearances to combustible and non-combustible materials listed below. See also Fig. 6.

A. Top 12 inches (306 mm)

B. Front 4 inches (102 mm)

C. Back 0 inches

D. Sides 4 inches (102 mm)

E. Bottom 12 inches (306 mm)

Clearances from any exhaust vent pipe are dependent upon the clearance requirements of the stainless steel vent pipe manufacturer. Single wall stainless steel (AL29-4C) vent pipe (vent type rated for Category III appliances) must be used when exhaust venting this appliance. See 2.9 Venting.

2.7Mounting installation

Warning: before starting installation:

B check that there are no loose parts inside the appliance

Bensure that gas pipe, gas valve, mixer, fan and burner have no damage and are properly fitted.

Front cover should be removed (see

iinstructions on page 4) in order to inspect components visually.

The GWH-635-ES is design certified for mounting on a wall. Secure the wall mounting bracket provided with the heater to a wall surface. See Fig. 7.

Do not install this appliance on a carpeted wall or over floor covering which is combustible, such as carpet. The heater must be mounted on a wall using appropriate anchoring materials.

If the mounting bracket is unable to line up on two wall studs it is recommended that support board(s), either 1x4's or ½" (minimum) plywood first be attached across a pair of studs and then the heater should be attached to the support boards. The heater should be kept level on the wall surface. See Fig. 7.

Expansion and contraction of piping due to changing water temperature in the pipes imparts movement to the heater which, if mounted directly to a brittle, friable board, such as plasterboard, can cause failure of mounting.

Before installing the unit, be certain you have the correct heater for your type of Gas - Propane or Natural Gas. Identification labels are found on the shipping box, and on the rating plate which is located on the right side panel of the cover.

Fig. 7 Mounting the heater

2.8Combustion air requirements

The GWH-635-ES is a sealed water heater and it is recommended that outdoor combustion air be piped to the unit. When combustion air is piped to the unit (TWIN PIPE SYSTEM) the combustion air pipe system may be constructed of either 3" PVC, aluminum or galvanized pipe. See Fig. 11, 12 and 13. Select a point for building penetration being sure that the necessary clearance on the outside of the building, between the combustion air pipe and the exhaust vent terminator of the appliance, can be maintained, see Fig. 16. NOTE: Observe all local building codes when penetrating a building wall.

NOTE: The combustion air inlet location on the side of a building must never be less than 3 feet away from the units exhaust vent terminator, see Fig. 16 Table 3.

The heater has the ability to operate without combustion air being piped to it from the outside, provided there is an adequate amount of combustion air available in the room area. Observe the following instructions concerning combustion air when following the SINGLE PIPE (exhaust venting only) SYSTEM only and follow Fig. 14 and 15 for proper setup.

•Appliances located in unconfined spaces:

–a) An unconfined space is one whose volume is greater than 50 cubic feet (1.42 cubic meter) per 1000 Btu per hour (292.81 Watts) of the combined rating of all appliances installed in the space. That would be 8750 cubic feet (247.8 cubic meter) for the GWH-635-ES alone.

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