Tankless water heater repair and maintenance
A tankless heater that is flushed once a year lasts about twice as long as a tank. One that is never flushed throws error codes, loses flow and fails early. We do the annual service and the repairs in between.
What goes wrong with tankless heaters
Common faults we fix
- Error codes under loadOften an undersized gas supply, a blocked vent or a dirty burner. We diagnose rather than guess.
- Hot, then cold, then hotThe “cold-water sandwich”, usually flow sensing or a flow rate below the unit’s minimum. Sometimes a recirculation setting fixes it.
- Low hot-water flowScale in the heat exchanger, or a dirty inlet filter. A flush usually restores it.
- No hot water at allIgnition, gas supply or a failed component. We carry common parts and can source the rest quickly.
- Water on the floorA condensate drain problem or a failed fitting. Not usually the unit itself.
The annual service
We isolate the unit, circulate a descaling solution through the heat exchanger to clear mineral deposits, clean the inlet filter and the burner, inspect the venting and condensate path, check water flow and pressure, and test the safety controls. Seattle’s soft water means scale builds slowly, but it still builds.
If your unit was installed without isolation valves, we can add them during the first service so every service after is quick.
Repair or replace?
A tankless unit under ten years old with a single failed part is worth repairing. One that is older, with a corroded heat exchanger, or that was undersized from the start, is usually better replaced with a correctly sized unit. We will tell you which, with the numbers.
Licensed, local, and on the record
- Licensed Bonded and insured in Washington
- Founder 15+ yrs in the plumbing trade
- Always Free estimates
- Available Same-day service
- Our promise 100% satisfaction guaranteed
Maintenance questions
How often should a tankless water heater be flushed?
Once a year in Seattle. More often on well water or if the unit sees heavy use.
Can I flush it myself?
If it has isolation valves and you have a pump and a bucket, yes. Most people have us do it so the burner, venting and safety controls get checked at the same time.
Do you service units you did not install?
Yes.
Talk to a Seattle plumber today
Tell us what is happening and we will give you a free, written estimate. Same-day service is available for most calls. No pressure, no obligation.
Serving Seattle, Shoreline, Bellevue and Mercer Island.