Troubleshooting Guide By Symptom; Noise - Navien NP-180 Service Manual

5.27. Troubleshooting guide by symptom

5.27.1. Noise

Error type
Defective
installation
Vibration
noise
Blower vibration
Defective flow
Regular
noise
Malfunction of
water adjustment
Gas and air
differential
Noise at
pressure error
ignition
(Pop, Beep,
Explo-sive
ignition)
Differential
pressure
setting error
Noise during
combustion
Boiling noise
©Navien America Inc. 2010
Cause
Incorrect level setting or fixing error
Check the fixing state, and reinstall the unit.
Vibration caused due to defective blower FAN balance.
Touch the blower. If vibration is significant, replace the blower.
If intermittent noise occurs during operation, check the blower.
noise
If vibration noise occurs during operation of the product, and stops
when the case lid is removed, check the blower.
Rotating noise due to foreign substance entered into the flow sensor.
sensor
Noise due to repeated opening/closing of water adjustment valve
due to a defective PCB.
valve
1. Gas differential pressure adjustment error
Adjust differential pressure with the pressure adjusting screw on the
main gas valve.
DIP S/W 1,2 ON (S/W 3 MIN),
If noise occurs at standard value, adjust setting above/ below
the standard.
2. Excessive gas supply due to defective proportional valve on the
main gas valve.
Check if the proportional valve wire is open, and if there is a problem,
replace the main gas valve..
3. Gas supply error due to defective air pressure sensor.
4. If the same error is repeated, it is due to a defective PCB.
Beep if the gas pressure is excessive due to defective adjustment
of differential pressure between gas and air.
Noise similar to the boiling noise
Adjust Stage 3 MAX differential pressure by model on
the specification table.
How to check the boiling noise:
Boiling noise occurs if the water temperature rises to149
(65 ~75 ).
1. The heat exchanger is clogged partially due to defective welding.
Replace the heat exchanger if the error occurs from the start of
the installation.
2. The heat exchanger is clogged due to foreign substance.
Clean the main heat exchanger by removing scale.
Replace the main heat exchanger if the error continues after
the cleaning.
124
NR/NP series service Manual
Check method
~167
Version 2.0