NSS Product Knowledge and Specifications 4 — Questions and Answers
Question 1: What is the built-in buffer tank capacity in Navien NPE-A series units that support ComfortFlow technology?
- 0.28 gallons
- 0.56 gallons (Correct answer)
- 1.0 gallon
- 2.0 gallons
Correct answer: 0.56 gallons
The NPE-A series includes a 0.56-gallon internal buffer tank that stores pre-heated water to eliminate the cold water sandwich effect.
Question 2: What is the primary purpose of the ComfortFlow feature in Navien NPE-A series units?
- Increasing maximum BTU output
- Eliminating the cold water sandwich effect during intermittent draws (Correct answer)
- Reducing gas consumption during standby
- Lowering the minimum activation flow rate
Correct answer: Eliminating the cold water sandwich effect during intermittent draws
ComfortFlow uses an internal buffer tank and recirculation pump to eliminate the cold burst of water between hot water draws.
Question 3: Which NPE-A series feature allows the internal recirculation pump to activate based on a set schedule?
- NaviLink timer mode
- Demand-activated recirculation
- Temperature-controlled polling
- Timer-based recirculation mode (Correct answer)
Correct answer: Timer-based recirculation mode
The NPE-A series supports timer-based recirculation mode, which activates the internal pump at user-programmed times to pre-heat the recirculation loop.
Question 4: What is the minimum flow rate required to activate the burner on Navien NPE series tankless water heaters?
- 0.26 GPM
- 0.50 GPM (Correct answer)
- 0.75 GPM
- 1.0 GPM
Correct answer: 0.50 GPM
NPE series units require a minimum flow rate of 0.50 GPM to activate the burner and begin heating water.
Question 5: What is the purpose of the secondary heat exchanger in Navien NPE condensing units?
- Heating domestic water only
- Extracting additional heat from exhaust gases to warm incoming cold water (Correct answer)
- Storing hot water for recirculation
- Filtering combustion air before the burner
Correct answer: Extracting additional heat from exhaust gases to warm incoming cold water
The secondary heat exchanger recovers latent heat from flue gases, preheating cold inlet water and producing condensate, which is the hallmark of condensing technology.
Question 6: What does the NaviLink Wi-Fi module allow a homeowner or technician to do remotely?
- Replace the igniter via app command
- Monitor unit status, adjust setpoints, and view error history (Correct answer)
- Perform gas pressure calibration wirelessly
- Override the high-limit switch remotely
Correct answer: Monitor unit status, adjust setpoints, and view error history
NaviLink provides remote monitoring of unit status, temperature setpoint adjustment, and error code history via a smartphone app.
Question 7: When an NPE series unit detects a freeze condition in its internal components, what action does it automatically take?
- It shuts down completely and locks out
- It activates the burner and circulates water internally to prevent freezing (Correct answer)
- It drains the heat exchanger automatically
- It sends an alert only but takes no action
Correct answer: It activates the burner and circulates water internally to prevent freezing
The built-in freeze protection activates the burner intermittently to circulate and warm water inside the unit when sensor temperatures approach freezing.
NSS Product Knowledge and Specifications 4
What is the built-in buffer tank capacity in Navien NPE-A series units that support ComfortFlow technology?