Navien Condensing Water Heater NPE-150S

Turn off the electric power, gas, and water shut-off valve.

Wait for the water heater to cool down.

Drain all water from the water heater.

Diagnose issues and error codes before disassembly.

Handle all parts carefully during removal.

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

List any parts replaced during maintenance

Place a bucket under the water heater to collect residual water.

Press the Power button to turn off the power to the water heater.

Close the water supply valve on the inlet to the water heater or turn off the water supply at the water main.

Open all hot water faucets completely to drain water from plumbing lines.

Remove the pump inlet filter from the bottom of the water heater.

Turn off the gas supply to the unit

Disconnect the unit from the power supply

Locate the fuse housing shown in Figure 3 and open it to expose the fuse

Replace the old fuse with the new part

Ensure the new fuse is of an equivalent rating and properly fixed inside the housing

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 Ignition Transformer insulated cables

Remove the 2 screws from the flame rod

Remove the flame rod wiring connector

Remove the flame rod from the burner assembly and replace with the new part

Reconnect the 2 ignition transformer insulated cables to the new flame rod

Place the new flame rod back onto the burner assembly and secure it by using the 2 screws