Flushing and descaling a tankless heater
Minerals in water leave scale inside the heat exchanger, and scale restricts flow and lets the unit overheat. Manufacturers typically call for periodic flushing, and the interval depends on your water and how much hot water you use.
A flush connects a small pump and a bucket or reservoir of descaling solution to the unit's service valves, circulates it through the heat exchanger and rinses it clean. We also clean the inlet screen, check for error codes and confirm the vent and condensate drain are clear.
Wilsonville's annual water report does not list a hardness figure, so test your tap or ask the utility for its latest report. A unit that fires on and off, shows scale error codes or has lost flow is telling you it needs service now.
When to call about a tankless heater
| Symptom | Common cause | What we do |
|---|---|---|
| Cold water between hot bursts | Low flow rate, scale or a sensor fault | Clean the inlet screen, flush, test sensors |
| Error code on the display | Ignition, venting, flow or scale | Read the code, inspect, repair or flush |
| Water temperature swings | Scale or a dirty flow sensor | Descale and test the sensor |
| Takes a long time to deliver hot water | Long pipe run, no recirculation | Discuss a recirculation pump |
| Water leaking from the unit | Failed fitting or internal leak | Shut off supply, repair or replace |
Tankless heater showing an error code?
Call with the code number and the make. A technician can tell you what the code usually means.
Tankless installation and recirculating pumps
A tankless install is bigger than a tank swap because the unit can need a larger gas line, special venting and a condensate drain. We measure the gas load against the manufacturer's requirements before quoting.
Many homeowners ask about adding a recirculating pump to a tankless system, since the long wait for hot water at a distant sink is the usual complaint. A pump or a built-in recirculation mode moves hot water through a return path so it is ready at the tap, and it works with a dedicated return line or a crossover valve.
In newer neighborhoods such as Villebois and Frog Pond, ask the builder or the HOA about venting and exterior wall rules before choosing where a wall-hung unit will go.
Tankless or tank: the honest comparison
Where tankless wins
- Endless hot water for long showers and back-to-back use
- Frees closet or garage floor space
- Long life with regular flushing
Where a tank wins
- Lower upfront price and simpler install
- Works with most existing gas or electric supply
- Easier for any plumber to service
If your current tank is failing, see water heater replacement, and for the planning side read water heater installation.
What affects the price of tankless service
You get a clear price before work starts. These details move it.
Related plumbing services
A failed unit is covered under water heater repair, and we serve Sherwood and nearby towns for tankless work too.
Frequently asked questions
Follow your manufacturer's schedule, and flush more often if the water is hard or the unit shows scale codes. Test your tap or ask the utility for its water report to understand your water.
Yes. The technician isolates the unit, circulates descaling solution, rinses it, cleans the inlet screen and checks the vent and condensate drain.
This usually comes from low flow through the unit, scale, a clogged inlet screen or a sensor issue. Flushing often solves it.
Yes. We check whether your home has a return line and pick a pump or built-in recirculation mode that suits it.
Yes. A leaking unit is an emergency. Shut off the water to it and call the 24/7 line.
It depends on how you use hot water and what your gas line and venting can support. We lay out the numbers and trade-offs and let you decide.