Navien Water Heater Error Code 442: How to Fix It

Q: What does Error 442 mean on Navien?

Error 442 indicates a DHW priority fault. The water heater's control logic detected a conflict in prioritizing domestic hot water demand, often due to a faulty flow sensor or control board issue.

Q: How do I reset Navien Error 442?

Power cycle the unit: turn off power at the breaker for 30 seconds, then turn it back on. This may clear temporary faults. If the error returns, further diagnostics are needed.

Q: Can I use my Navien water heater with Error 442?

It's not recommended. The error may cause the unit to shut down or operate inefficiently. Running with the fault could lead to further damage. Fix the issue before regular use.

Q: Is Error 442 common on Navien tankless heaters?

It is not one of the most common errors, but it can occur, especially if the flow sensor becomes dirty or if there are wiring issues. Regular maintenance helps prevent it.

Q: How much does it cost to fix Navien Error 442?

If DIY, the cost is minimal (cleaning supplies or a new flow sensor ~$20-50). Professional service call fees are $100-200 plus parts and labor.

Abstract

Error Code 442 on a Navien tankless water heater indicates a DHW (domestic hot water) priority fault. This means the unit's internal logic detected a conflict in prioritizing hot water demand, often due to a faulty flow sensor or control board issue. The water heater may shut down or fail to heat properly.