Navien Condensing Water Heater NPE-240A

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

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

Loosen the clip that secures the hose to the condensate trap, and then pull off the hose

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 stainless clip and four screws at the flow sensor

Detach the 2 wire connectors that connect the flow sensor to the PCB

Replace the old flow sensor with the new part

Reinstall the flow sensor into the cold water inlet pipe and reattach the stainless clip

Ensure that the flow sensor is properly connected to the cold water inlet pipe and that the clip is tightly holding the two parts together

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

Disconnect the mixing valve wire connector

Remove the 2 stainless steel clips from the water adjustment valve connections

Remove the water adjustment valve

Place a bucket under the water heater

Replace the cap and the retaining clip

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 mounting screw from the fan assembly

Remove the fan assembly bracket with the attached intake port

Disconnect the wiring connector from the fan assembly

Remove the 4 screws from the gas valve connection