Troubleshooting 107
5.1.16 439Error
Error occurrence conditions and check items
Error
Description
E439
Flow sensor error
As one or more units are operating in the cascade system, if no flow is detected while the system opens the
water adjustment valve, the system considers it as a defective flow sensor. The system displays 439E (cleared
manually) on the front panel and switches the unit operation into the Lock-Out mode (gas valve and ignition
transformer locked).
Check items
1. Check the supply of cold water while the cascade system is disabled. (frozen/locked valve).
2. Defective flow sensor.
3. Defective PCB.
Check flow sensor connector (CON6)
Clean water flow sensor
Disable cascade operation and
open faucet
Check cold water supply
NO
Is there water flow?
Yes
Содержание NPE-180A
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