Bosch Powerstar AE 115 Instructions D'installation Et D'utilisation page 24

Troubleshooting
Water Temperature fluctuates
Cold mix, heater
deactivates
Fluctuating water pressure
Changing flow rate.
Water supply connected to
the outlet of the unit.
Tab. 14
24
If inlet water temperature is over 70°F, water may be very hot out of the tap. This
requires a lot of cold water to be added in order to get a usable hot water
temperature. The addition of too much cold water will overpower hot water demand
from the water heater. This slows the flow within the water heater, decreasing it
below the activation point, which shuts off the heater. The end result is nothing but
cold water coming out of the outlet. Increase the flow rate by cleaning or replacing
fixtures and lower the setting on the temperature adjustment knob.
If the water pressure in the home is erratic and the water flow is not consistent
while a tap is opened, then the temperature of hot water will fluctuate. The
minimum water pressure for the home should be 30psi or greater. For people on
well systems the minimum pressure range is 30-50psi. The use of a pressure
reducing/regulating valve is an effective way to maintain constant water pressure to
the water heater. Watts brand 25AUB- ¾" or N35B-¾" pressure reducing/regulating
valves or equivalent is suggested.
Major changes in flow rate can adversely affect the output water temperature of the
heater. Increases from one major fixture running to multiple fixtures running at one
time can cause the temperature to fluctuate. Stay within the heater's specifications.
See Fig. 11.
6 720 800 414 (2011/09)