Navien Condensing Water Heater NPE-180S

Turn off the gas supply to the unit

Disconnect the unit from the power supply

Turn off the water supply to the unit

Removal of Old Air Pressure Sensor

Remove the air pressure sensor wiring connector (Figure 11)

Remove the hose from the air pressure sensor

Remove the 2 screws that attach the air pressure sensor to the burner assembly

Pull out the air pressure sensor

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

Replace the cap and the retaining clip

Turn off the gas supply to the unit

Turn off the 120V power supply to the unit

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

Remove the 3 screws at the hot water outlet fitting to loosen the 2-way valve

Remove the stainless steel clips from the connections

Disconnect the wiring connector at the 2-way valve

Remove the 3 buffer tank screws and pull out the buffer tank

Rinse the filters with clean running water (cold)

Scrub the filters clean with a brush if necessary

Reinsert and tighten the filters

Check that all the parts are in place

Inspect for any leaks after refilling

Describe any issues encountered during the procedure