Troubleshooting - Bosch WH36 Installation Manual And Operating Instructions

16 | Troubleshooting

7 Troubleshooting
DANGER: Risk of electric shock!
▶ Always switch off the electricity supply
to the unit before you remove the cover.
Cold water only – Neon light off
Flow rate is too low Verify the flow rate out of fixture is at or above the minimum activation rate required for the unit to
activate. (Activation rate: WH36 = 0.8 GPM).
Plumbing crossover To test for a plumbing crossover, turn off power supply to the heater. Close installer supplied cold water
shut off valve (if none installed, install before proceeding). Open all hot water taps supplied by the
heater. Wait 5 minutes and check all taps. Any water running is a sign of a plumbing crossover. Consult a
local plumber or service person for help in correcting a plumbing crossover. To return the heater to
service, reinstall cover, open the inlet water supply to the heater and open all hot water taps. Let all taps
run until there is no air coming out of the fixtures. Shut off all hot water taps. Turn power supply on to the
heater. Return heater to service. (This procedure will prevent the heating elements from burning out).
The flow transducer is Turn off the power supply to the heater and remove the cover. Observe if the flow transducer "spins"
not spinning when the water is turned on. Please note the flow transducer spins at a high speed and can appear to be
stopped when actually spinning. It is recommended to observe the flow transducer without water
flowing, then turn on a hot water tap while observing the flow transducer. If the flow transducer is not
spinning, remove and flush flow transducer, noting the Do's and Dont's on page 14. See the technical
support section of www.bosch-climate.us for more detailed instruction on removing the flow transducer.
No electricity at the Have a licensed electrician verify proper wiring and adequate voltage on the terminal block inside the
heater or one of the water heater. See the "Electrical connections" section on page 10 of this manual.
supplies has failed
Table 10
6 720 647 022 (2013/04)
Important: If you are unable to perform the tasks listed below,
or need additional assistance please contact your original
installer/licensed electrician.
Tronic 5000C