Bosch AE115 - Manual (Page 14)

Using an Ohmmeter to check for Premature element failure
LEFT MODULE Top View RIGHT MODULE Top View
Meter probes Ohm Reading Meter probes Ohm Reading
Outer to Outer 10.5 ± 0.5 Ohms Outer to Outer 10.5 ± 0.5 Ohms
Middle to Middle 11.5 ± 0.5 Ohms Middle to Middle 11.5 ± 0.5 Ohms
Inner to Inner 15.0 ± 1 Ohms Inner to Inner 21.0 ± 1 Ohms
Note: On AE115 model, there is no middle element.
Water flow too low
There are
restrictions in the
plumbing Obstructions in the water path can restrict the flow of water through the heater.
Verify the heater’s inlet filter screen, faucet aerators, showerhe ads and whole
house filters are clear of debris. Verify proper flow on the outlet side of the heater
with the hot water pipe disconnected. Maximum flow rates for each unit are as
follows. AE115 = 2.3gpm, AE125 = 3.5gpm.
Water supply
pressure too low Verify incoming water supply is at least 30psi. For people on well systems, the
recommended pressure range is 30-50psi.
Outlet shut-off
valves are set too
low Adjust installer supplied outlet valve as described below:
• Completely open both installer supplied inlet and outlet shut-off valves at the
heater. (if none installed, install before proceeding)
• Completely open hot water on the highest flowing hot water fixture served by
the heater (i.e. bathtub).
• Slowly close the outlet shut-off valve, slowing the water flow rate until the
temperature at the hot water faucet corresponds to the values given on
Graph 1 on Page 8 of the manual, or desired water temperature is reached.
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