NPE‑S2 FAQs

½” gas pipe can be used when installing a NPE-2 condensing gas tankless water heater as long as it is sized appropriately.

Pipe size, length of gas pipe, and pressure drop are all factors that affect gas delivery.

Please refer to the National Fuel Gas Code gas pipe sizing table to ensure you have sufficient gas supply for the unit.

No, it is not required that the NPE-2 condensing tankless gas water heater be the first appliance off the gas meter.

It can be installed using the existing infrastructure and can go in place of a traditional tank water heater so long as the gas line is sized appropriately and can deliver sufficient gas supply to the unit.

The NPE-2 is approved to be vented with 2”vent material (maximum length of 75 feet, maximum of 6 elbows, and reduce 8 linear feet per 90° elbow). 3” vent material can also be used (maximum length of 150’, maximum of 8 elbows, and reduce 5 linear feet per 90° elbow).

Approved vent materials are PVC Schedule 40, CPVC Schedule 80, Approved Polypropylene, and stainless steel.

Yes, with the NPE-2 condensing tankless gas water heater you can use PVC Schedule 40, which allows for zero inch clearance to combustibles.

Yes, the NPE-2 has built in display and control allowing for simple and easy operation.

ComfortFlow technology is a proprietary system that incorporates a buffer tank and recirculation pump.

The buffer tank will reduce “cold water sandwich” effects commonly found with tankless products and the recirculation pump will minimize the amount of time required for delivery of hot water to fixtures.

Yes, the NPE-2 can be mounted outdoors using the Navien Outdoor Vent Kit.

It is recommended the unit only be mounted outdoors in mild climates.

Please follow proper instruction procedures outlines in installation manual.

Yes, the NPE-2 is gas field convertible.

The default gas type for the unit will be Natural Gas (NG). To convert the unit for LP use, please use gas conversion kit supplied with unit.

This should only be performed by a qualified service agency in accordance with Navien America’s instructions.

The NPE-2 is approved for use in residential, commercial, and heating (combination only) applications.

If used in commercial or heating application, the warranty will be adjusted to 8 years on the heat exchanger, 5 years on any other parts, and 1 year labor.

Monday - Friday

Pacific - 4am-8pm
Mountain - 5am-9pm
Central - 6am-10pm
Eastern - 7am-11pm

Saturday - Sunday - Holidays

Pacific - 5am-5pm
Mountain - 6am-6pm
Central - 7am-7pm
Eastern - 8am-10pm

Navien Inc. (Headquarters)

20 Goodyear
Irvine, California 92618
Phone: 800-519-8794, 949-420-0430

Navien America Inc. (Branch Office)

325 Route 70 East
Cherry Hill, New Jersey 08034
Phone: 800-519-8794 Fax: 856-354-5099

Navien America Inc. (Branch Office)

346 Millway Ave. Unit 7
Vaughan, ON L4K 3W1
Phone: 800-519-8794 Fax: 905-532-9976

Please see the following attachment on where you can locate your serial number.

1. Locating Serial Number

Residential
Details about our residential warranty for Navien’s NPE series tankless water heater, NCB series combi-boiler and NHB series condensing boiler can be found here.

Commercial
Details about our commercial warranty for Navien’s NPE series tankless water heater and NHB series condensing boiler can be found here.

The applicable period for this labor allowance for all water heater models is One (1) year from the effective date.

The payment and amount of any payment are subject to approval at Navien’s sole discretion.

The labor allowance will be paid based on Navien’s schedule of labor allowances.

Because our product involves water, electricity, and gas, there is only a limited amount of troubleshooting that can be done with a homeowner/end-user.

We recommend contacting your original installer or a Navien Service Specialist (NSS) to troubleshoot the unit.

NOTE: Charges will apply for service calls outside of 1 year labor period and/or non-warranty issues. Please see terms of our labor warranty.

Because our product involves water, electricity, and gas, there is only a limited amount of troubleshooting that can be done with a homeowner/end-user. We recommend contacting your original installer or a Navien Service Specialist (NSS) to troubleshoot the unit. NOTE: Charges will apply for service calls outside of 1 year labor period and/or non-warranty issues. Please see terms of our labor warranty.

The issue is most likely the flow sensor inside the unit is not spinning properly.

We recommend opening and closing the pressure relief valve (should be located near the outlet of the unit). Depending on amount of debris affecting the flow sensor, this may help temporary. We recommend contacted your original installer or an NSS to service the sensor.

If you feel like there is an issue with your unit, please have someone contact Navien Technical Support while in front of the unit with your Serial Number ready. We recommend that a license contractor, original installer, or NSS contact is the person who calls us, so we may do in depth troubleshooting to determine if there is a part failure.

Navien Technical Support will be unable to send out parts without registration of product (Serial Number, Date of Installation, Homeowner Information, and Installer Information).