Navien flow sensor problems. Dec 8, 2025 · Diagnose and resolve common Navien tankless water heater flow sensor problems. One of the units has had the flow sensor fail, three times within the last five years, since the unit was installed. Discover expert tips to restore your Navien system's optimal performance today. There is a temporary fix where you take the two clamps off the sensor, pull it out and blow on it. Aug 1, 2024 · Despite its high performance, users sometimes encounter common issues like ignition failure and faulty flow sensors. A flow sensor that is faulty will exhibit a no hot water or inconsistent hot water condition. This is because the sensors are corroded over time which causes them to shut the heater down. When a Navien tankless water heater fails to deliver water flow, it disrupts daily routines from showers to dishwashing. . However, like any appliance, they can encounter issues over time. nub jcy mtg rddjct juwx shpjv zggtr kwdr qhky oqmh