Flush a tankless heater every one to two years depending on use. If yours shows an error code, note it before you call; it usually tells us what to bring.
Signs you need tankless water heater service
- An error code on the controller
- Water that turns hot, then cold, then hot
- Lower hot water flow than before
- The unit firing then shutting off
- No flush since installation
How we handle it
- Read the codeError history points to ignition, flame, venting, flow or overheating faults.
- Descale the heat exchangerA pump circulates descaling solution through the unit using the isolation valves.
- Clean filters and check ventingInlet screens, air intake and vent runs are cleared and checked.
- Test under loadWe run several fixtures to confirm stable temperature at real flow.
What tankless water heater service usually costs around Greenville
| Job | Typical range |
|---|---|
| Tankless descaling flush | $195 to $345 |
| Isolation valves added for future service | $215 to $395 |
| Ignition or flame sensor repair | $245 to $595 |
Ranges reflect common jobs in Greenville and nearby towns. Access, materials and the hour of the call change the final number, and you get an exact price before work starts. Compare prices across all services.
What you can do before we arrive
Write down the error code and the brand before you call, and check that the gas supply valve to the unit is open. Many codes are tied to gas supply or a blocked vent.
What we see in Upstate homes
Greenville Water is soft, so scale builds slowly here, but many homes on well water in the outer county see mineral buildup much faster. If your home is on a well, plan on flushing yearly.
Keeping it from coming back
Keep a flush schedule, clean the inlet filter screen when we flush, and do not stack storage against the unit's air intake.
Questions about tankless water heater service
What is a cold-water sandwich?
A brief burst of cold water between hot ones when a fixture is turned off and back on. It is normal for many tankless units and can be reduced with a recirculation setup.
Can I flush my own tankless heater?
If it has isolation valves, many owners can. If it does not, we can add them so future flushes are simple.
Why is my tankless heater showing an error?
Codes usually mean ignition, venting, gas pressure, or flow problems. Tell us the code and the brand when you call.
Areas we cover for tankless water heater service
Plumbcraft sends tankless water heater service crews from Greenville and Belton across the Upstate.