Installation instructions

3.7Gas piping & connections

Before connecting the gas supply, check the rating plate on the right side of the heater to be sure that the heater is rated for the same gas to which it will be connected.

In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54.

In Canada: The installation must conform to CGA B149 INSTALLATION CODES and/or local installation codes.

Warning: DO NOT connect to an unregulated or high pressure propane line or to a high pressure commercial natural gas line.

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. If overpressure has occurred, such as through improper testing of the gas lines or malfunction of the supply system, the gas valve must be checked for safe operation.

GAS CONNECTIONS

BInstall a manual gas shut off valve (installer supplied) on the gas supply line.

BInstall a union when connecting gas supply.

B The minimum diameter required for any appliance connector used is ¾”.

B National Fuel Gas Code requires that a sediment trap (drip leg) be installed on gas appliances not so equipped. The drip leg must be accessible and not subject to freezing conditions. Install in accordance with the recommendations of the serving gas supplier.

When connections are made, check for gas leaks at all joints. Apply some gas leak detection solution to all gas fittings. Bubbles are a sign of a leak. A combustible gas detector may also be used to detect for leaks.

Danger: If you have a leak, shut off the gas. Tighten appropriate fittings to stop leak. Turn the gas on and check again with a gas leak detection solution. Never test for gas leaks using a match or flame.

GAS LINE SIZING

The gas supply piping should be sized according to the applicable code for a maximum draw of 120,000 BTUH (GWH450ESR) or 96,000BTUH (GWH345ESR).

Measure the length of gas supply line and use the tables in Fig. 26 or the gas line manufacturer’s sizing tables to determine the pipe diameter necessary to accommodate the BTU demand of the unit. If there are more gas drawing appliances on the line, size the gas line according to the total maximum amount of BTU draw for all appliances.

Note: Under sizing the gas line may result in diminished output and improper operation. See chapter 3.8 for the procedure to confirm gas pressure.

Inlet gas particle screen

Gas piping

Fig. 25

6 720 607 909

23

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Bosch Appliances GWH-345/450-ESR-N, GWH-345/450-ESR-L manual Gas piping & connections, GAS Connections
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GWH-345/450-ESR-L, GWH-345/450-ESR-N specifications

Bosch Appliances has long been recognized for its innovative and high-quality home appliances, and the GWH-345/450-ESR-N and GWH-345/450-ESR-L water heaters are no exception. These models offer exceptional efficiency and reliability, making them ideal choices for modern households seeking dependable water heating solutions.

One of the standout features of the GWH-345/450-ESR series is their impressive energy efficiency. Engineered with cutting-edge technology, these units operate with high thermal efficiency ratings. This not only translates to reduced energy bills for consumers but also supports environmentally friendly practices by minimizing energy consumption. The tankless design eliminates the need for a storage tank, providing hot water on demand while ensuring that no energy is wasted in heating and re-heating stored water.

Both models come equipped with advanced safety features. The integrated combustion management system ensures precise control of the combustion process, which not only enhances heating efficiency but also reduces the risk of overheating. Additionally, the built-in safety mechanisms, such as flame failure protection and overheat protection, provide consumers with peace of mind knowing their home is protected.

These Bosch water heaters also feature a user-friendly digital display that allows for easy temperature adjustment and monitoring. The intuitive interface enables users to set their desired water temperature with precision, ensuring comfort and convenience. Furthermore, these models are designed for quiet operation, making them suitable for installation in various locations within the home without causing disruptive noise.

The construction of the GWH-345/450-ESR-N and GWH-345/450-ESR-L models is robust, featuring high-quality materials that ensure durability and longevity. The compact and sleek design allows for flexible installation options, even in smaller spaces. With a variety of venting options available, including direct vent and power vent configurations, these heaters can fit seamlessly into different home layouts.

In summary, Bosch Appliances GWH-345/450-ESR-N and GWH-345/450-ESR-L models represent the pinnacle of modern water heating technology. With their energy-efficient performance, advanced safety features, user-friendly controls, and durable construction, these water heaters are designed to meet the demands of today’s homes while delivering reliable hot water whenever needed. These innovative appliances reinforce Bosch's reputation as a leader in home heating solutions, ensuring that customers can enjoy hot water with confidence and peace of mind.
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