Tankless water heaters are sold as low-maintenance. And compared to a 50-gallon tank sitting in your garage, they are — but “lower maintenance” isn’t the same as “no maintenance.” Most Atlanta homeowners who call us about a struggling tankless unit haven’t done a single maintenance step since installation.
Here’s the honest breakdown of what tankless maintenance actually involves, what Atlanta’s water supply does to these units, and when to call a plumber versus doing it yourself.
Why Atlanta’s Water Accelerates Tankless Maintenance Needs
Atlanta sits in one of the softer water regions of Georgia, but “soft” doesn’t mean clean. The city’s treated water supply — fed from the Chattahoochee River and Lake Lanier — carries sediment, dissolved minerals, and chlorine that build up inside tankless units over time.
The heat exchanger is the most vulnerable part. It’s a coiled copper component that heats water on demand — and it’s the first place sediment settles. In Atlanta homes, we typically start seeing scale buildup impact performance between years 2 and 4 without proper flushing. By year 6 or 7 without maintenance, heat exchanger replacement is often the outcome.
The Annual Descale Flush — What It Is and Why It Matters
This is the single most important maintenance task for any tankless water heater. You’re running a descaling solution through the heat exchanger to dissolve mineral deposits.
What you need:
- Two isolation valves on the cold inlet and hot outlet (most professional installs include these)
- A submersible pump and hoses to circulate the solution
- White vinegar (food-grade, undiluted) or a commercial descaling kit
- 45–60 minutes
If your installation doesn’t have isolation valves with flush ports, this is a plumber job. The process for a properly installed unit:
- Close the hot and cold isolation valves
- Connect the submersible pump hoses to the flush ports
- Fill the bucket with 3–4 gallons of undiluted white vinegar
- Run the pump for 45–60 minutes
- Flush with clean water for 5–10 minutes
- Reopen the isolation valves and restore the unit
The Inlet Filter Screen — Easy and Often Forgotten
Every tankless unit has a small mesh filter screen on the cold water inlet. In Atlanta homes with older plumbing, this screen can clog within months — especially after city water line work in your neighborhood. Clean it at least once a year. If you notice reduced hot water flow, check this first before calling anyone.
Gas-Specific Maintenance
Venting inspection. Condensing tankless units produce acidic condensate that can corrode PVC vent pipes. We check vent connections for corrosion, disconnection, or blockage on every maintenance call.
Burner assembly. This is a licensed plumber task — gas components require professional servicing.
If you smell gas near the unit at any time, shut off the gas supply immediately and call us at (404) 800-3569.
Signs Your Tankless Unit Is Overdue for Service
- Cold water sandwich — hot water, then a burst of cold, then hot again. Often indicates scale buildup.
- Reduced hot water output — the unit struggles to keep up with demand it previously handled easily.
- Error codes on the display — document the code and call.
- Unexpected shutoffs mid-shower — overheating protection triggered by scale.
Maintenance Schedule by Age
- Year 1–2: Clean inlet filter at 12 months. Descale flush at 18–24 months.
- Years 3–7: Annual professional service. Annual descale flush.
- Years 8–12: Annual service plus closer look at the heat exchanger.
- Year 12+: Start having a replacement conversation. A well-maintained tankless can hit 15–20 years.
When to Call Fix & Flow
Call us at (404) 800-3569 or book a maintenance visit online for gas units of any age, units without flush ports, or any unit showing error codes or inconsistent output.
For more on tankless water heater installation and repair in Atlanta, see our Tankless Water Heater page. If you’re weighing options, see our water heater types and replacement guide.