37Error - Navien NP-180 Service Manual

5.21. 37Error

Error occurrence conditions and check items.
Error
If the water leak sensor signal is detected while the water heater is ON, the system
displays 37E (cleared manually). The water heater enters the Lock-Out mode
(gas valve and ignition transformer closed), and closes the flow control valve to
prevent further water leak.
37E
For the cascade system
Internal water
1. If the water leak signal is sensed in one out of two units, the system blocks direct
leak
water of the all units to prevent water leak.
2. If three or more units are installed, the system blocks cold water for the
concerned unit only.
3. To block the cold water, the system completely closes the water adjustment valve.
1. Visually check heat exchanger and piping for leaks.
2. Check if the PCB water level sensor works normally.
Check items
3. Check if the PCB works normally.
Is there any water leakage
inside water heater?
Yes
Replace leaking part
©Navien America Inc. 2010
Description
Is there any water leakage
No
detector normally
operating?
Yes
Check connector
110
NR/NP series service Manual
Replace water leakage detector
Version 2.0