Navien CH-180, Service Manual, Page: 59 / 155

57
Check method
Failure
mode
Cause Check method
Check the circulation pump.
In the error condition, the circulation pump and the fan run
continuously.
1. Check power supply to the circulation pump (AC 120V).
2. Replace the PCB if power is not supplied.
Thudding
noise
caused by
minimum
flow
Defective
circulation
pump
Defective
3-way valve
The heating
strainer is
clogged.
The main
heat or the
hot water
heat
exchanger
is clogged.
Thudding
noise
caused by
minimum
flow
Touch the heating outlet pipe as the heating function is on, and
check if the temperature changes.
If there is no change in temperature, check the operation error in
the 3-way valve hot water mode.
Red+Black (AC 120V): Heating
Blue+Black (AC 120V): Hot water
Defective 3-way valve if power is normally supplied
Defective PCB if power is not supplied.
1. Separate inlet/outlet pipe of the main heat exchanger, and blow
air with mouth to check if the pipe is clogged.
2. If the 01 Error occurs when hot water is used only, check if the
hot water heat exchanger is clogged.
1. Check if the strainer is clogged with debris.
2. Check the cause of debris if the strainer is clogged.
(Aluminum distributor oxidized steel, etc.)
<Heating strainer>
G
<Checking strainer>
G
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0