Bosch Appliances GWH 2700 ES NG Maintenance and service, Annual maintenance table Every year

Maintenance and service

6Maintenance and service

Warning: Always turn off the electrical power supply, turn off the manual gas shut off valve and turn off the water shut off valves whenever servicing.

Caution:

B Check and clean the complete water heating system once a year.

B Carry out a maintenance overhaul if necessary. Immediately repair defects to avoid damage to the system.

Pressure relief valve

•Manually open the pressure relief valve to ensure proper operation.

Inlet water filter

•Verify the inlet filter screen is clean and undamaged. The inlet water filter is located inside the cold water inlet fitting on the right side of the appliance (See Fig. 53, page 32). Close installer supplied cold water shutoff and loosen slotted screw on inlet fitting. Water will drain from the appliance. Remove cylindrical filter inside.

Annual maintenance table

		Every year
1.	Inspect venting system	X
2.	Inspect combustion chamber	X
3.	Inspect burner	X
4.	Inspect condensate trap	X
5.	Inspect water filter	X

Table 16 Annual maintenance

The unit should be checked once a year by a gas technician. If repairs are needed, the repairs should be done by a gas technician.

6.1Annual maintenance

(To remove front cover, see page 6.)

Venting System

•Venting system - inspect inside of flue pipe for any blockage or restriction. Observe burner flames during heater operation. (Vent pipe must be removed). Inspect the combustion air inlet pipe for blockage or debris. Inspect combustion air and exhaust terminations for blockage or debris.

Combustion chamber

•Inspect burner observation window (Fig. 64, #10) for cracks or spillage of flue gases. Observe burner flames during heater operation. Flames should be steady and blue with no signs of yellowing. Yellow burner flames are an indication of improper combustion. Refer to Section 3.4 & 3.3 of this manual to ensure that exhaust system and combustion air supply meets manufacturer's specifications.

Fig. 53 Water filter

1Inlet water filter

2 Water filter

Descaling

•In areas where the water supply has a high mineral content (see Table 13, page 25), the heat exchanger should be periodically flushed with a descaling solution. Scale build up will shorten the life of the water heater and damage resulting from scale is not covered under warranty. Refer to section 6.3 for detailed instructions on descaling the heat exchanger.

Heat exchanger fin coils

•Inspect heat exchanger fincoil for soot build-up or blockage. To access fincoil, venting must be removed from flue gas exhaust accessory. With venting removed and inspect fincoil below with a flashlight. If there is evidence of soot build-up or blockage, the heat exchanger should be removed by a professsional and cleaned thoroughly. To remove the heat exchanger, consult service bulletin at www.boschhotwater.com.

6.2Winterizing for seasonal use

Installation instructions state that the water heater must not be installed in a location where it may be exposed to freezing temperatures. If the heater must be left in a

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