NSS Installation and Setup Procedures 4

Question 1

When installing a Navien unit in a mobile home, which additional requirement applies compared to a standard residential installation?

Accepted Answer

The unit must be listed and approved for mobile home installation

Answer

Units installed in mobile homes must carry a listing and approval specifically for mobile home use per HUD and manufacturer requirements.

Question 2

Which Navien service menu function is used to manually purge air from the water circuit after initial installation?

Accepted Answer

Maintenance mode → pump purge cycle

Answer

The pump purge cycle in maintenance mode runs the internal pump to purge trapped air from the water circuit.

Question 3

What is the correct orientation for installing the Navien NPE series unit's intake and exhaust vent pipes when using a concentric vent kit?

Accepted Answer

Exhaust in center pipe, intake in outer pipe

Answer

In a concentric vent configuration, exhaust travels through the inner center pipe while combustion air enters through the outer annular space.

Question 4

During a Navien combi-boiler installation, what is the minimum expansion tank size recommendation for a typical residential heating system?

Accepted Answer

4.4-gallon tank

Answer

Navien recommends a minimum 4.4-gallon expansion tank for residential hydronic heating systems connected to a combi-boiler.

Question 5

What is the purpose of the NPE series 'buffer tank sensor' input on the Navien PCB?

Accepted Answer

Reads the temperature of a buffer or storage tank to control space heating output

Answer

The buffer tank sensor input allows the Navien unit to monitor tank temperature and modulate output to maintain target heating setpoints.

(NSS) Certified Navien Service Specialists Practice Test