Tankless unit flashing an error code or not heating? Our licensed Portland plumbers diagnose and repair gas and electric tankless heaters the same day — ignition, flow, scale and venting faults — at an upfront price.
A tankless (on-demand) water heater only makes hot water when it can ignite, breathe, and sense enough water flow. When any of that is off, you get no hot water, lukewarm water, or an error code on the display. Most faults are repairable the same day — and unlike a tank heater, a tankless unit is built to be serviced part-by-part rather than replaced.
Gas and electric units — we diagnose the root cause, not just reset the code.
Closed valve, clogged inlet filter, failing flow sensor, gas-supply issue, or scale in the heat exchanger.
Dirty igniter or flame rod, gas pressure, or a blocked burner keeping the unit from firing.
Demand beyond the unit's GPM, scale buildup, or a restricted inlet filter limiting hot water.
Mineral scale in the heat exchanger triggers maintenance codes and weak heating — cleared by descaling.
Blocked intake or exhaust venting causing combustion errors and safety shutdowns.
Frequent hot-cold-hot swings from a failing flow sensor or an undersized unit.
Seeing a different code (Noritz, Takagi, Bosch, Rheem)? Read it to us on the phone and we'll tell you what it means and bring the right parts.
Over time, dissolved minerals collect inside the heat exchanger and choke a tankless unit's performance — triggering scale codes (Rinnai LC, Navien E760), weak heat, and premature wear. A professional descaling flush circulates a cleaning solution through the unit for about 45–60 minutes to clear it out.
We recommend a flush at least once a year. Staying on top of it is the single best way to extend a tankless heater's life and avoid sudden no-hot-water calls.
Tankless units last 15–20 years and are designed to be repaired part-by-part. Repair almost always wins unless:
Time for a new one? See tankless installation or replacement.
We repair gas and electric tankless units from Rinnai, Navien, Noritz, Takagi, Bosch and Rheem, among others, and carry common flow sensors, igniters, flame rods and control boards.
| Professional descaling flush | $150 – $300 |
| Common part repair (sensor, igniter, valve) | $150 – $600 |
| Major repair (heat exchanger, control board) | $600 – $1,300 |
Estimates for guidance; you get an upfront flat-rate quote before any work, with no after-hours surcharge.
We read every brand's codes, carry common tankless parts, and descale on site — same-day across Portland, with no overtime fees.
From the first call to a clean finish, our licensed Portland plumbers handle tankless water heater repair with upfront, flat-rate pricing and no overtime fees — day, night, weekends and holidays.
Call (971) 386-1515Read us your error code and we'll tell you what's wrong.
Tankless units need gas, airflow, and adequate water flow to fire. No or low hot water is usually a closed valve, clogged inlet filter, failing flow sensor, scale in the heat exchanger, or an ignition fault. We diagnose it the same day.
On Rinnai, 10/11/12 point to combustion, ignition and flame problems; 14/16 are overheating; LC means scale. On Navien, E012 is flame loss, E016/E030 are overheating, and E760 means a descaling flush is due. We read the code and fix the underlying fault.
At least once a year, and more often if you see scale codes. A professional descaling flush takes about 45–60 minutes and clears mineral buildup from the heat exchanger to restore performance.
Most issues — flow sensor, igniter, flame rod, control board, scale — are repairable. Replacement makes sense only if the unit is near its 15–20 year lifespan or the repair exceeds ~50% of a new install. See tankless installation.
Most repairs run roughly $150–$1,300 depending on the part; a descaling flush is about $150–$300. You get an upfront, flat-rate quote before we start, with no after-hours surcharge.
A short cold burst between hot draws is often normal, but frequent swings can signal a failing flow sensor or a unit that's undersized for your demand. We can test and advise.
No ignition usually means a gas-supply problem, failing igniter, dirty flame sensor, blocked burner, or a blocked vent (Rinnai 10/11, Navien E003). We pinpoint and repair it the same day.
Gas and electric tankless units from Rinnai, Navien, Noritz, Takagi, Bosch and Rheem, among others. We carry common parts and can often repair the same day.