American Water Heater BBCN375T754NV Service Information, High Temperature Limit Switch ECO

6.After it has been determined that each appliance connected to the venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas burning appliance to their previous conditions of use.

7.If improper venting is observed during any of the above tests, the venting system must be corrected.

WARNING

FAILURE TO CORRECT BACK DRAFTS MAY CAUSE AIR CONTAMINATION AND UNSAFE CONDITIONS.

HIGH TEMPERATURE LIMIT SWITCH (ECO)

The water heater is equipped with a manual reset type high limit (Energy Cutoff) sensor. The high limit switch interrupts the main burner gas flow should the water temperature reach 195°F (90°C). The high limit switch must be manually reset by turning the power to the water heater off for 5 seconds then back on and cannot be reset until the water temperature drops below 120°F (49°C). It is important that a serviceman be called to determine the reason for limit operation and thus avoid repeated thermostat resetting.

1.Provide complete combustion of gas.

2.Cause rapid ignition and carryover of flame across entire burner.

3.Give reasonably quiet operation during ignition, burning and extinction.

4.Cause no excessive lifting of flames from burner ports.

If preceding burner characteristics are not evident, check for accumulation of lint or other foreign material that restricts or blocks the air openings to the heater or burner.

WARNING

SOOT BUILD-UP INDICATES A PROBLEM THAT REQUIRES CORRECTION BEFORE FURTHER USE. CONSULT WITH A QUALIFIED SERVICE TECHNICIAN.

Should the main burner or burner air openings require cleaning, remove the burner and clean with a soft brush. Clean main burner orifice with a suitable soft material.

CHECK FOR GOOD FLOW OF COMBUSTION AND VENTILATING AIR TO THE UNIT. MAINTAIN A CLEAR OPEN AREAAROUND THE HEATER AT ALL TIMES. DO NOT STORE COMBUSTIBLES OR FLAMMABLE LIQUIDS NEAR OR AROUND AN APPLIANCE.

WARNING

THE ON/OFF SWITCH MUST HAVE BEEN IN THE OFF POSITION FOR AT LEAST 5 MINUTES. This waiting period is an important safety step. Its purpose is to permit gas that may have accumulated in the combustion chamber to clear. IF YOU DETECT GAS ODOR AT THE END OF THIS PERIOD DO NOT PROCEED WITH LIGHTING. RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS WEAK, MAY INDICATE PRESENCE OF ACCUMULATED GAS SOMEPLACE IN THE AREA WITH RISK OF FIRE OR EXPLOSION. SEE THE FRONT PAGE FOR STEPS TO BE TAKEN.

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.

SERVICE INFORMATION

The installer may be able to observe and correct certain problems which may arise when the unit is put into operation. HOWEVER, it is recommended that only qualified servicemen, using appropriate test equipment, be allowed to service the heater.

FOR YOUR SAFETY AND SATISFACTORY OPERATION, IT IS RECOMMENDED THAT THIS HEATER BE CHECKED ONCE A YEAR BY A COMPETENT SERVICE PERSON.

USERS OF THIS water heater SHOULD BE AWARE THAT GAS COMPONENTS WEAR OUT OVER A PERIOD OF TIME. THE GAS CARRYING COMPONENTS OF THIS water heater SHOULD BE INSPECTED FOR PROPER OPERATION PERIODICALLY BY A QUALIFIED SERVICE TECHNICIAN.

MAIN BURNER AND IGNITER

Check main burner (figure 7) at least every 6 months for proper

flame characteristics. The main burner should display the following

characteristics:

BURNER HEAD

ASSEMBLY

BURNER TUBE

ASSEMBLY

H.S.I.

ASSEMBLY

FIGURE 7. MAIN BURNER AND IGNITER ASSEMBLY

CHECKING GAS INPUT

For appliance installation locations with elevation above 2000 ft.(610m) refer to HIGH ALTITUDE INSTALLATIONS section of this manual for input reduction procedure.

With this heater in operation, determine whether it is receiving the full rated input of gas. This may be done by timing the gas meter and measuring gas pressure with a gauge or manometer. When the heater is operating at full capacity (full gas input) it should consume approximately 1 cubic foot of gas in the time shown in table 6.

TABLE 6

INPUT CHECK TIME REQUIRED TO CONSUME 1 CU. FT. OF GAS

Type of Gas	BTU Per Cu. Ft.	Time Required To Con-
		sume 1 Cu. Ft. of Gas
Natural	1050	50.3 Seconds

Use this formula to “clock” the meter. Be sure that other gas consuming appliances are not operating during this interval.

3,600 X H = Btu/h

T

T= Time in seconds needed to burn one cubic foot of gas. H = Heating value of gas in Btu’s per cubic foot of gas. Btuh = Actual heater input rate.

Example:

T = 47.2 seconds/ft3

H = 1,050 Btu/ft3 (natural gas) Btuh = ?

3,600 X 1,050 = 75,100 Btu/h (22Kw)

50.3

Compare the actual input rate to that given on the heater’s rating plate. In the example, the full input rate should be 75,000 Btu/h (22 Kw) for natural gas.

VENT SYSTEM

Examine the venting system every 6 months for obstructions and/or deterioration of vent piping.

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