Bosch AE115 - Manual (Page 15)

Water Temperature Too Hot
Temperature dial
set too high Turn the temperature knob located on the bottom of the water heater
counterclockwise for cooler temperatures.
There are
restrictions in the
plumbing Obstructions in the water path can restrict the flow of water through the heater
causing
overheating. Verify the heater’s inlet filter screen, faucet aerators,
showerheads and whole house filters are clear of debris. Verify proper flow on the
outlet side of the heater with the hot water pipe disconnected. Opening hot water
isolation valve fully may be necessary. Maximum flow rates for each unit are as
follows. AE115 - 2.3gpm, AE125 - 3.5gpm.
Inlet water
temperature is too
warm Verify the heater is being feed with cold water only. This water heater is not
designed for preheated water or recirculation applications. Increase flow rate
where ever possible. Replacing low flow showerheads and aerators with higher
flowing (GPM) ones may be necessary.
Water Temperature Fluctuates
Cold mix, heater
deactivates 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. See service bulletin TWH-E2-04 at www.boschhotwater.com for further
troubleshooting on this symptom.
Fluctuating water
pressure 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.
Changing flow rate 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 Graph 1 on page 8.
PowerStar
LIMITED 10 YEAR WARRANTY
COVERAGE
BOSCH THERMOTECHNOLOGY CORP. guarantees this water heater to the original owner of the water
heater at the original installation location against defects in material and workmanship for the periods
specified below.
WARRANTY PERIOD
1. The Heating Modules – If the original heating module leaks or fails within ten (10) years from the
date of original installation of the water heater because of a defect in material or workmanship, Bosch
Thermotechnology Corp will furnish to such an owner a replacement heater of the then
- prevailing
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