Navien Tankless Water Heater Repair in San Jose, CA

Navien problems we repair most in San Jose

Santa Clara Valley water is hard, gas pressure in older neighborhoods sags under load, and a lot of local units were installed with undersized gas lines. That combination produces a predictable short list of failures.

• No hot water at all — ignition lockout, gas valve failure, or a tripped high-limit switch
• Hot then cold ('cold water sandwich') — scaled heat exchanger, failing flow sensor, or a recirculation loop set up wrong
• Error codes E003, E012, E016, E030, E109, E110, E407 and E438 that keep returning after a reset
• Rumbling, kettling, or a burning smell from mineral buildup baked onto the exchanger
• Leaks at the isolation valves, pressure relief valve, or condensate drain
• NaviLink Wi-Fi that drops, and recirculation schedules that never trigger

How our repair visit actually works

You get a licensed water heater specialist, not a general handyman. We start at the control board because the unit already recorded what went wrong.

• Pull the stored fault history and operating hours from the control panel
• Measure static and dynamic gas pressure — the single most-missed cause of ignition faults
• Inspect venting, intake air, condensate path, flame rod, and igniter
• Check inlet water filter and flow sensor, and test scale level in the exchanger
• Explain the cause in plain language, quote the repair before we start, then fix it

Repair or replace? An honest answer

A Navien with a good heat exchanger is almost always worth repairing — the exchanger is the expensive part and it carries a long factory warranty on residential installs. We recommend replacement only when the exchanger is cracked or scaled beyond recovery, when parts for a discontinued model are no longer available, or when the unit was installed so far out of spec that correcting it costs more than a new, properly installed system. Joseph J. Castro, our owner, will tell you straight which side of that line your unit falls on.

Warranty-safe parts and workmanship

Navien's residential warranty depends on correct parts and correct service records. We install Navien-specified components, document the work, and keep your coverage alive. Every repair is backed by our own workmanship guarantee and performed under California contractor license #1008381.