Installation instructions

3Installation instructions

3.1Introduction

Please follow these instructions. Failure to follow instructions may result in:

BDamage or injury.

BImproper operation.

BLoss of warranty.

If you are unable to perform the tasks required to install this heater properly, please contact a locally licensed plumber or gas technician.

Please contact Bosch Water Heating with any questions.

3.2Proper location for installing your heater

Carefully select the location of the water heater. For your safety and for proper heater operation, you must provide combustion air to the heater and a proper exhaust vent system.

Follow the guidelines below:

B 1. Locate the heater where venting, gas and plumbing connections are feasible and convenient.

B2. The hot water lines should be kept short to save energy. Centrally locating the water heater is best. It is always best to have hot water lines insulated.

Warning: The water in this water heater is cold and always remains cold except for the times that hot water is being used. DO NOT INSTALL IN AN AREA WHERE IT COULD FREEZE.

Drain the heater entirely if freezing temperatures are anticipated in area where heater is installed. See chapter 4.5 for draining instructions.

To prevent freeze damage from residual water in the heater, introduce short bursts of compressed air (20-40psi) through these connections to remove the residual water in the horizontal pipes and water valve.

Warning: Flammable materials, gasoline, pressurized containers, or any other items or articles that are potential fire hazards must NOT be placed on or adjacent to the heater. The appliance area must be kept free of all combustible materials, gasoline and other flammable vapors and liquids.

Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig.

Warning: Place the heater in a location where water leaks will do NO DAMAGE to adjacent areas.

3.3Heater placement and clearances

The GWH 425 PN is design certified for installation on a combustible wall (see 3.4 Mounting installation) provided the wall is not covered with carpet or other fabric material. For installations in an alcove or closet, maintain the minimum clearances to combustible and non-combustible materials listed below. See also Fig. 4.

A. Top 12 inches (306 mm)

B. Front 4 inches (100 mm)

C. Back 0 inches

D. Sides 4 inches (100 mm)

E. Bottom 12 inches (306 mm)

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