TO TURN OFF GAS TO APPLIANCE
1.Close main manual gas valve and slide the gas valve button to the OFF position.
PRESSURE TAP
PRESSURE REGULATOR
MANUAL GAS VALVE
PEEPHOLE
WATER TEMPERATURE CONTROL
To adjust water temperature use water flow selector, at heater. For hot water rotate control Knob to the right.
GAS VALVE BUTTON
PILOT IGNITOR BUTTON
WATER FLOW
SELECTOR
PRESSURE REGULATION
The pressure regulator supplied with the water heater is adjusted to operate on the gas specified on the rating plate and:
-in Canada, is factory preset to deliver gas at the high altitude pressure setting listed on the rating plate and as shown below.
-in the U.S., is factory preset to deliver gas at the standard altitude setting listed on the rating plate and as shown below.
The pressure setting of the gas pressure regulator should be checked at installation to assure that the setting is correct for the gas being used and the altitude at which the appliance is installed. See rating plate on the unit, or the chart below for proper settings.
In Canada for a heater being installed at standard altitude (0- 2.000 ft. elevation) the manifold pressure should be reset at installation to value shown on the rating plate, or chart below for standard altitude.
The gas pressures specified below refer to flow pressure taken at the pressure tap in the gas inlet pipe (just above pressure regulator, figure 5) while the heater is operating at full input.
Appliance Regulator Pressure Setting
Type of Gas |
| Pressure tap | Altitude | |
kPa |
| Inches, W.C. | ||
|
|
| ||
natural | 1.41 |
| 5.7 | standart |
propone | 2.61 |
| 10.5 | (0.2,000 ft.) |
natural | 1.14 |
| 4.6 | high |
propane | 2.09 |
| 8.4 | |
Note: The high altitude ratings listed are Canadian Gas Association high altitude ratings for the appliances and are only valid in Canada. In the U.S. the National Fuel Gas Code, ANSI Z 223.1/NFPA 54, recommends for high altitude installations, above 2000 feet that the input rate be reduced 4% for each 1.000 feet above sea level.
Turn counter- | Turn |
clockwise: | clockwise: |
more water | less water |
- Warm | - hot |
The control knob regulates the water temperature by ad- justing the flow rate of the water through the heater:
-Maximum flow rate through the heater is 5L/min, (1.3 U.S. gal/min.) with temperature rise of 25°C (45°F) at full input.
-Minimum flow rate through the heater is 2.3 L/min. (0.6 U.S. gal/min) with temperature rise of 55°C (99°F) at full input.
For normal hot water use the control knob of water flow
selector should be turned clock wise ( 
) to stop and remain in that position. This will permit control of remote temperature by mixing more or less cold water with the hot water supplied by the heater.
Note: If flow rate is adjusted to a point where water flow through the heater is less than 2.3 L/min. the main burner will
Warning: Hot water can produce 3rd degree burns, in 6 seconds at 60°C (140°F)
In 30 seconds at 54°C (130°F)
HIGH TEMPERATURE LIMIT SWITCH
The BOSCH W125K…instantaneous gas water heater is equipped with a high temperature unit switch with a set point of 90°C (194°F). If the water temperature at the sensing bulb should exceed 90°C (194°F) the switch will open, interrupting the safety circuit and stopping gas flow to the pilot and main burner.
Pilot outage as a result of high limit operation indicates that the heater is not functioning properly. The heater should be checked by a qualified serviceman and the reason for malfunction corrected. To relight pilot follow instructions provided on the unit.
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