Circulation Pump - Navien NCB-700-2S+/42K Service Manual

4.7.14 Circulation Pump

Item
Function
Fault
Symptoms
Error codes
Diagnostics
Testing/inspection
information
56 System Details
1. Provides internal or external water circulation.
2. Internal circulation minimises the effects of temperature fluctuations. External circulation quickly
delivers hot water to taps and results in water conservation.
Unable to detect or measure water flow.
1. Water inside the boiler system freezes.
2. Water temperature fluctuations when the boiler is set to internal recirculation.
3. Hot water takes a long time to be available at taps when the boiler is set to external recirculation.
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1. Visual inspection: Check the circulation pump connection wire.
2. Check the water filter for obstructions.
3. Voltage test: Test the voltage meets the specifications shown below.
YELLOW-WHITE
ON: AC 230 V
●
OFF: 0 V
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Description