Troubleshooting
WARNING
Always switch off the electricity supply to the unit before you remove the cover.
IMPORTANT:
If you are unable to perform the tasks listed below, or need additional assistance please contact your original installer/licensed electrician.
| Cold water only – Neon light off |
Flow rate is too | Verify the flow rate out of fixture is at or above the minimum activation rate |
low | required for the unit to activate. (Activation rates: AE115 = 0.6 GPM, AE125 = 0.8 |
| GPM). |
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The water supply | Verify plumbing connections are correct (See Diagram 1, Page 4). Reconnect the |
is connected to | water supply to the inlet of the unit (marked blue). |
the outlet of the |
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unit |
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Plumbing | To test for a plumbing crossover, turn off power supply to the heater. Close |
crossover | 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). |
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The flow | Turn off the power supply to the heater and remove the cover. Observe if the flow |
transducer is not | transducer "spins" when the water is turned on. Please note the flow transducer |
spinning | 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. See the technical support section of |
| www.boschhotwater.com for more detailed instruction on removing the flow |
| transducer. |
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One or more of the | Turn off the power to the heater, remove the cover and locate thermal cutouts on |
heating module | the top of each heating module. Try resetting each cutout by pushing the reset |
thermal | button located in the center of the cutout. Determine and fix the cause of the |
has tripped | overheating. Obstructions in the water path can restrict the flow of water through |
| the heater causing it to overheat. Verify the heater’s inlet filter screen and all |
| outlets served by the heater are clear of debris. Ensure the heater is not being fed |
| preheated water. This water heater is designed for a cold water supply only. If |
| thermal cut out does not reset, check for continuity through each cutout (less than |
| 0.5 Ohms). If any cutout reads more than 0.5 Ohms or open, then it may be |
| defective and should be replaced. |
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No electricity at | Have a licensed electrician verify proper wiring and adequate voltage on the |
the heater or one | terminal block inside the water heater. See the “Electrical connections” section on |
of the supplies has | Page 5 of this manual. |
failed |
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