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Navien is known as one of the biggest manufacturer of on demand water heaters. They solely product tankless water heaters because they believe that instant on demand hot water is the future of the market.  Navien was the first to come out with a condensing tankless water heater and thus they are bound to have some additional issues. This post is aimed at addressing and solving some of the common problems associated with their early generation systems. THE IMAGE ON THE RIGHT has an example of how the error code on Navien Tankless Water Heaters look like. This error codes are used by Navien specialist to evaluate the problems that are going on with your hot water heater. Below is a list of few of the common issues that are listed by customers who have Navien tankless water heater.

  • Navien flow sensor issues
  • Navien Control board failures
  • Navien Heat exchanger cracks

The flow sensor
Early navien models had flow sensors that would easily corrode and shut the unit down as the buildup would impair operation. There is a temporary fix where you take the two clamps off the sensor, pull it out and blow on it. The fix that Navien has made is to change the sensor over to stainless steel, you can replace the part to prevent this unexpected shut down. Also an additional fix is to install a 5 micron filter in the water inlet right before the navien.

Navien Control Boards or Motherboards
These do fail relatively frequently and symptoms would be that the unit turns on, then off, then on, and then off repeatedly or possibly, fails with error code 03 (ignition failure). There are a few other issues that the board can cause but the only real solution is to power cycle the unit (un-plug and plug back in) or replace the Navien control board.

Cracking Heat Exchanger
This isn’t near as frequent as the problems listed above but it is an issue none the less. A heat exchanger should be replaced immediately; it’s a breach containment allowing exhaust gases to enter your home. The heat exchanger is under navien warranty.