Maintenance & Service; Trouble Shooting - Bosch 125HX LP Installation And Operating Instructions Manual

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.
Water Valve (Part # 8707006353): The water valve on this
heater should be serviced periodically. Lubricate component
36 on page 16 with a small amount of silicon, faucet or
lithium grease every two years to keep its o rings fresh and
pushrod sliding smoothly. Every 3-5 years replace
component 36 on page 16. The frequency will depend on
the mineral content of the water and conditions of use or
whenever signs of corrosion appear at the gas and water
valve joint. Periodically check that the water inlet filter (#27
on page 16) is clean as well. NOTE: If water valve is removed,
be sure to also inspect the o ring seals on the ends of the
left and right hand side water pipes before re-installing.
Lubricating the o rings is recommended.
Pilot Flame: The pilot flame should burn with a clean,
sharp, blue flame and should resemble the diagram in
Fig.10. If the flame is soft and yellow, the pilot burner orifice
may need to be cleaned or replaced. The pilot flame should
be approximately 2 inches long, extending past the flame
sensor. If the flame is too small, it will not reach the flame
sensor and the burners will not come on.
3mm
Fig. 10 - Characteristic Pilot Flame
6 720 606 562 (02.03)
Correct gap between pilot
burner tip and electrode tip
Piezo Electrode
Flame sensor
Piezo
Electrode
To clean the pilot burner and/ or the pilot orifice : Turn
off the gas to the unit. Set the On/Off switch to Off (position
). Remove the cover of the heater. To do so, 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 pilot orifice should be cleaned or replaced. Do
not enlarge the orifice.
Do not use any wire or sharp object to clean orifices. Natural
gas orifices are large enough that you can usually clean
them by blowing through them. LP orifices, on the other
hand, are too small to clean and should be replaced.
To access the pilot orifice, remove 2 screws holding pilot
assembly in place. Then loosen compression fittings to
expose pilot orifice.
Fig. 11 - Pilot burner with pilot orifice
Main Burner Flames: The main burner flames should be
blue, with a more intense blue cone in the center core.
Yellow flames could be a sign of wrong size gas orifices or
dirty burners, or a blockage on the heat exchangers fins.
If some burners have yellow flames while others have good
flames, it is likely that dust, lint or spider webs have partially
clogged the burner venturis. To clean the burners, contact
a gas service person.
Mineral Scale Build-up: The AquaStars heater, when
operated at lower temperature settings, do not accumulate
mineral build-up. If however, the heater is used at the higher
temperature settings and the water has a high mineral
content, periodic descaling may be necessary. The heating
coils should be flushed with a descaling solution. The
descaling is done only to the heat exchanger. The
chemicals will damage the hydro-generator and other parts.
Consult your dealer or Controlled Energy for instructions.

TROUBLE SHOOTING

Introduction
The AquaStar 125HX burners are activated by a water flow
valve. Numerous water related problems can cause this
water valve to malfunction such as: Insufficient water flow
volume to activate the burners at its minimum flow
requirement; Dirt in the water flow valve causing it to
malfunction; Sediment build-up in faucet aerators, or shower
heads; Uneven pressures between cold and hot. (with single
lever faucets) Plumbing cross overs. These water flow
related problems can cause the heater to deliver less than
its full output, or to fail to ignite or to shut down completely.
PILOT ORIFICE
11