©Navien America Inc. 2010 NR/NP series service Manual92Version 2.05.11. 16ErrorError occurrence conditions and check items.DescriptionError16EBimetaloverheatedCheck itemsIf the overheat controller on the heat exchanger operates during combustionstop of the boiler, the system displays the 16E (manually cleared) message on theremote controller and the PCB. The boiler switches into Lock-Out, and performspostpurge continuously and operates the pump.If the overheat sensor signal is detected within 10 min after the combustion isstopped, no error is displayed, and the system does not start combustion until theoverheat sensor is returned to normal.Is HTL* normally operation?YesNoReplace PCBReplaace HTLCheck the resistance betweenteo white wires of CN 13:short-circuit(016E)Check the resistance betweenteo white wires of CN 13:short-circuit(030E)Caution: Measuning should be done at leat 30 minutesafter error.1. Check if the main heat exchanger is clogged.2. Check if the overheat controller works properly.3. Check the hot water output/input temperature sensor.4. Check the PCB DIP S/W capacity setting.5. Check if the PCB works properly.
