Flow switch, Models 1600P/425PN | Bosch Appliances GWH 425 HN

AQ4 Installation instructions

2.7 Flow switch

Replacement piping and flow switch is included for 1600P/425PN and 1600H/425HN water heaters. Check your model number on the right side of the water heater cover to confirm which procedure to follow.

Models 1600P/425PN

1.Shut off cold water supply isolation valve. If none installed, install before proceeding. Open hot water tap to relieve water pressure if water is already connected.

2.Remove and save clip on lower right side of heat exchanger.

3.Using a flat head screw driver remove and save pin from front, right side of water valve. (Fig. 8)

4.Remove copper pipe and set aside.

5.Find and connect the black flow switch to the bushing and pipes shown in Fig. 9A. Secure together with supplied clips.

6.Position flow switch and connecting pipe and bushing in place of the copper pipe that was removed.

7.Reinstall pin in water valve and clip on heat exchanger connection.

8.Connnect the three prong Molex connector cable to the flow switch.

9.Connect control cable from vent motor to Molex connector cable with wire nuts as seen in Fig. 10.

Models 1600H/425HN

1.Shut off cold water supply isolation valve. If none installed, install before proceeding. Open hot water tap to relieve water pressure if water is already connected.

2.Remove and save clip on lower right side of hydrogenerator.

3.Remove and save pin from front, right side of water valve using a flat head screwdriver. (Fig. 8)

4.Remove copper pipe and set aside.

5.Find and connect the black flow switch to the pipes shown in Fig. 9B.

6.Position flow switch and connecting pipes in place of the copper pipe that was removed. Secure together with supplied clips.

7.Reinstall pin in water valve and clip on heat exchanger.

8.Connnect the three prong Molex connector cable to the flow switch.

9.Connect control cable to Molex connector cable with wire nuts as seen in Fig. 10.

Water valve pin

Pipe to heat exchanger

Fig. 8 Water valve pin

	Connection to	Brass heat
		exchanger
	water valve
		bushing

Flow switch molex connector

Replacement pipe for pilot models

Fig. 9A 1600P/425PN flow switch connections

Connection to	Connection to
hydro generator	water valve

	Replacement
	pipes for	Flow switch
	hydro models	Flow switch
	hydro models	molex connector
		molex connector

Fig. 9B 1600H/425HN flow switch connections

Connections from	Connection from
Molex connector	vent motor (black
cable (white and	and red)
yellow)

Fig. 10 Flow switch electrical connections

8	AQ4 Manual

GWH 425 PN, GWH 1600 P, GWH 1600 H, GWH 425 HN specifications

Bosch Appliances have long been synonymous with innovation and reliability in the realm of home comfort solutions. Four notable models in their range of gas water heaters are the GWH 425 HN, GWH 1600 H, GWH 1600 P, and GWH 425 PN. Each unit is developed to meet diverse user needs while providing the highest levels of efficiency and performance.

The Bosch GWH 425 HN is a high-capacity unit catering to larger households or commercial environments. With an impressive heat output, this model ensures a consistent hot water supply when needed. Key features include advanced combustion technology for enhanced efficiency and reduced emissions, making it an environmentally-friendly choice. Its compact design allows for flexible installation options, fitting seamlessly into tight spaces. Additionally, the unit is equipped with an intelligent control system that optimizes performance based on usage patterns.

Moving on to the Bosch GWH 1600 H, this water heater is perfectly suited for smaller homes and apartments. It combines user-friendly operation with energy-saving capabilities. This model utilizes a unique modulating burner system that adjusts the flame intensity according to water demand, significantly lowering energy consumption. Furthermore, the GWH 1600 H incorporates a built-in safety system that ensures optimal operation under varying conditions.

The Bosch GWH 1600 P offers a similar capacity as the GWH 1600 H but with added digital functionalities. Users can expect advanced temperature settings and real-time monitoring through an intuitive digital display. This model prioritizes ease of use, allowing homeowners to customize their hot water experience effortlessly. The GWH 1600 P also reflects Bosch’s commitment to durability, featuring robust construction suitable for various environmental conditions.

Lastly, the Bosch GWH 425 PN is another versatile choice for those needing robust hot water production. It shares many characteristics with the GWH 425 HN, like high efficiency and smart technology. However, it distinguishes itself with innovative low-NOx technology, reducing nitrogen oxide emissions to meet stringent environmental regulations.

In summary, Bosch's GWH 425 HN, GWH 1600 H, GWH 1600 P, and GWH 425 PN represent a diverse selection of gas water heaters designed to suit different household needs. Whether it’s for a larger family or a compact apartment, these models provide efficient and reliable hot water solutions while employing advanced technologies to minimize environmental impact. With their focus on quality and customer satisfaction, Bosch Appliances continues to lead the way in the hot water industry.