NSS Maintenance and Repair Techniques

Question 1

How often should Navien units be descaled?

Accepted Answer

Annually

Answer

Navien recommends annual descaling of their tankless water heaters, especially in areas with hard water. This regular maintenance prevents the buildup of mineral deposits (scale) on the heat exchanger, which can significantly reduce efficiency, restrict water flow, and lead to premature component failure. Annual descaling ensures optimal performance and longevity of the unit.

Question 2

What is used to flush the system?

Accepted Answer

Pump and descaling solution

Answer

To effectively descale a Navien unit, a specialized descaling solution (typically a mild acid like citric acid) is circulated through the heat exchanger. This process requires a dedicated pump to push the solution through the system and hoses to create a closed loop, allowing the solution to dissolve mineral deposits without damaging components.

Question 3

What part must be inspected for blockage?

Accepted Answer

Inlet water filter

Answer

The inlet water filter is the first line of defense against sediment and debris entering the Navien unit from the water supply. Over time, this filter can become clogged, restricting water flow and potentially causing performance issues or error codes. Regular inspection and cleaning or replacement of this filter are crucial for proper operation.

Question 4

Why is heat exchanger inspection important?

Accepted Answer

Check for corrosion and scaling

Answer

The heat exchanger is the most vital component in a Navien unit, responsible for transferring heat to the water. Regular inspection is crucial to identify signs of corrosion, which can lead to leaks, and scale buildup, which reduces efficiency. Addressing these issues proactively ensures the unit's longevity and optimal performance.

Question 5

Which part is replaced when worn gaskets are found?

Accepted Answer

Gaskets

Answer

Gaskets are sealing components designed to prevent leaks between two mating surfaces, such as pipe connections or component housings. If worn or damaged gaskets are found during inspection, they must be replaced with new ones to ensure a proper, leak-free seal and maintain the integrity of the system.

(NSS) Certified Navien Service Specialists Practice Test

(NSS) Certified Navien Service Specialists Practice Test

NSS Maintenance and Repair Techniques