NSS Product Knowledge and Specifications 3

Question 1

Which venting materials are approved for use with Navien NPE series condensing tankless water heaters?

Accepted Answer

PVC, CPVC, and ABS

Answer

NPE series units accept PVC, CPVC, and ABS vent piping because their low flue gas temperatures are safe for plastic materials.

Question 2

What is the minimum natural gas supply pressure required for proper NPE series unit operation?

Accepted Answer

3.5" W.C.

Answer

Navien NPE series units require a minimum natural gas supply pressure of 3.5" W.C. to achieve rated performance.

Question 3

What is the maximum allowable static gas supply pressure for Navien NPE series natural gas units?

Accepted Answer

10.5" W.C.

Answer

The maximum static natural gas pressure for NPE series units is 10.5" W.C.; higher pressures can damage the gas valve.

Question 4

What vent pipe diameter options are available for Navien NPE-180A installations?

Accepted Answer

2" or 3" only

Answer

The NPE-180A supports 2" or 3" vent pipe, with 3" recommended when total equivalent vent length exceeds the 2" limit.

Question 5

What size condensate drain connection is provided on Navien NPE series units?

Accepted Answer

3/4"

Answer

NPE series units have a 3/4" condensate drain connection that must be piped to an approved drain location.

(NSS) Certified Navien Service Specialists Practice Test