Bosch Appliances 125B NG Water Heater User Manual


 
136 720 607 030
LIGHTING INSTRUCTIONS (as seen on front cover
of heater)
1. STOP! Read the safety information above on this plate.
2. The Gas valve must be turned off by sliding the gas valve
button to the far left under the OFF ( ) mark.
3. Wait five (5) minutes to clear out any gas. If you smell
gas, STOP! Follow “B” in the safety information above
on this plate. If you don’t smell gas, go to next step.
4. The pilot burner is located behind the peephole in the
front center of the jacket directly below this instruction
plate.
5. Slide the gas valve button to the right, under mark ( ).
6. Fully depress gas valve button and light pilot by pushing
“PILOT IGNITER” button ( ). This step may have to be
repeated.
7. Observe the pilot flame through the peephole. The gas
valve button should be held down at least 15 seconds
with pilot burning. When the gas valve button is released,
the pilot should continue to burn.
- If the gas valve button does not pop up when released,
stop and immediately call your service technician or gas
supplier.
- If pilot does not stay lit, repeat steps 1 through 7.
- If pilot will not stay lit after several tries, slide the gas
valve button to the left, under the OFF ( ) mark and call
service technician or gas supplier.
8. Once pilot remains lit, then release gas valve button. The
heater will now fire when water is drawn at a rate greater
than the threshold flow rate.
NOTE: If main burner should fail to ignite, make sure pilot is
burning. If not, repeat lighting steps 1 through 7.
NOTE: The 125B operates in two modes. See SETTING
THE WATER TEMPERATURE.
TO TURN OFF GAS TO APPLIANCE
Slide the gas valve button to the far left, under the off ( )
mark and close the gas supply to the heater.
SETTING THE WATER TEMPERATURE
The Aquastar 125B has a gas control that modulates burner
input in response to hot water flow. Its purpose is to ensure
that the hot water temperature will remain steady, although
the water flow demand may vary (down to ½ gal/minute).
Also, depending on the unit’s adjustable gas control slide
being set in the single flame ( ) or three flame ( )
setting, the 125B can produce and control comfortable hot
water temperatures as seasonal ground water temperatures
vary.
To adjust the temperature on the heater, turn on a hot water
tap. At the water heater, turn the temperature adjustment
knob (see Fig. 9) all the way to the right (clockwise) and set
the gas control slide to the three flame ( ) setting. This
will produce a temperature rise of approximately 90F at flow
rates between 0.5 and 2.0 gallons per minute. Given that
average incoming water temperatures are 50F in winter
months; this heater will produce approximately 140F water
at these flow rates. Turning the dial all the way to the left
Fig. 9 - Water Flow Control Knob
(counterclockwise) will produce a temperature rise of
approximately 45F for flow rates between 1.1 and 3.7 gallons
per minute. When setting the gas control slide to the single
flame ( ) setting and positioning the knob fully clockwise,
the heater will produce a temperature rise of approximately
55F at flow rates between 0.5 and 2.0 gallons per minute.
Turning the dial all the way the counterclockwise will produce
a temperature rise of approximately 33F for flow rates
between 1.1 and 3.7 gallons per minute. It is safest to select
a comfortable temperature and not have to mix in a
considerable amount of cold water. The positions you select
will depend on the temperature of the incoming water (50F
is average in the U.S.). In warm weather regions where the
incoming ground water is generally warmer, or during hot
weather months in other areas, a single flame ( ) setting
may be best. During the colder months, or in cold climate
areas, a three flame ( ) setting may be best. NOTE: The
knob setting will affect the activation point of the heater;
fully clockwise will allow the heater to activate at 0.5 gal/
minute. Fully counterclockwise will allow the heater to
activate at 1.1 gal/minute.
Do not supply the 125B with preheated water. For this type
of application, use the solar back-up model 125B LPS or
125B NGS.
If the inlet water temperature to the water heater is very
warm the heater can produce temperatures that may be
found to be too hot. A temperature balance shower valve
can automatically mix in cold water to reduce such hot water
temperature, in the event of any temperature instability with
the use of a temperature balance shower valve, refer to
shower valve manufactures instructions for internal
adjustment setting. Adjustments should be made to the
hottest setting in the shower valve. Additionally the
temperature control of the heater can be adjusted to produce
a more comfortable hot water temperature.
MAINTENANCE AND SERVICE
REVIEW MAINTENANCE TABLE ON THE
BACK OF THIS MANUAL
Approximately once a year, the AquaStar should be checked
and cleaned. To remove the front cover, first remove the
incandescent particle tray, then pull off the temperature
adjustment knob and unscrew and remove the plastic collar.
Pull main cover out toward you and lift up and out. THE
FOLLOWING OPERATIONS SHOULD BE PERFORMED
BY A QUALIFIED SERVICE PERSON:
Vent System: Should be checked annually. Clean and repair
as needed.
GAS CONTROL SLIDE
TEMPERATURE
ADJUSTMENT KNOB