Navien Condensing Water Heater NPE-210A

CAUTION: Servicing must be performed by a qualified service agency or gas supplier

List any parts replaced during maintenance

Turn off the gas supply to the unit

Disconnect the unit from the power supply

Turn off the water supply to the unit

Remove the pin that secures the condensate drain cap and then remove the cap

Use a bucket to collect the condensate

Detach the condensate piping from the unit

Remove the 3 screws located at the bottom of the unit that are attached to the condensate trap

Turn off the gas supply to the unit

Disconnect the unit from the power supply

Turn off the water supply to the unit

Remove the screws that hold the PCB in place

Disconnect all wiring connectors from the PCB

Remove the screws on the back of the case

Remove the old PCB and replace it with the new part

Reattach all wiring connectors to the PCB

Set the proper DIP S/W settings on the PCB

CAUTION: Authorized Personnel Only

Ensure only an authorized technician or licensed professional performs this procedure.

Gather necessary items for flushing

Press the Power button on the front panel to turn off the water heater.

Disconnect the power supply to the water heater.

Close the 'C' and 'D' valves on the hot and cold water lines.

Connect one tube to the 'A' valve and place the free end in the bucket.

Turn off the gas supply to the unit

Disconnect the unit from the power supply

Turn off the water supply to the unit and drain all water from the appliance

Remove the gas valve to gain access to the buffer tank

Remove the clip at the bottom of the buffer tank

Remove the 3 mounting screws from the buffer tank

Replace the old buffer tank with the new part

Reinstall the buffer tank using the 4 mounting screws