Hot Water - Navien NP-180 Service Manual

5.27.2. Hot water

Error
Remote controller
power off
Defective flow
Water heater
fails to work
Defective hot
water temperature
Hot water
setting error
Low hot water
temperature
Water mixed
with cold
No hot water
Check the pipe
from the valve
Pre-heating
Cold water
flows temporally
does not work
©Navien America Inc. 2010
Cause
Hot water does not run if the remote controller is switched off.
The water heater does not work due to the defective flow sensor.
The impeller does not rotate, if the axis is stuck due to foreign
substance.
If the impeller rotates normally, replace the hall sensor of the
sensor
flow sensor.
The sensor may be reused temporarily after cleaning, but
replacement must be considered preferentially.
The temperature is sensed higher than the actual temperature due to
a defective hot water (cold water) sensor.
Hot water temperature is low although hot water is recognized by
sensor
the remote controller.
The cold temperature sensor may not work without any symptom.
Check the hot water temperature setting on the remote controller.
The temperature of hot water at the tap is low while the temperature
is high at the hot water outlet.
Cold water and hot water are mixed due to improper pipe
installation.
water.
Cold water and hot water are mixed due to improper installation
of the tap.
1. The cold water valve is closed.
2. Check if the cold water filter is clogged with foreign substance.
3. The water adjustment valve is closed. (Refer to E34.)
4. Check if the cold water / hot water pipes are frozen during
the winter.
5. The main heat exchanger is clogged (by lime)
6. Low inlet water pressure
For the A model, the system performs the internal/
external circulation preheating when 24-hour timer is set on the
remote controller.
Therefore, make sure to check the time setting
126
NR/NP series service Manual
Check method
Version 2.0