A tankless water heater can provide hot water on demand, but it still needs routine care. Minerals in water can collect inside the heat exchanger, while blocked air vents or neglected filters can affect performance. A few simple checks can help you catch issues early, but maintenance steps vary by model and fuel type. Use your owner’s manual as the guide, and arrange professional service when a task involves gas, electrical components, or internal repairs.
Follow a Routine Care Schedule
Check the owner’s manual for the recommended maintenance schedule and instructions for your specific model. Inspect the area around the unit regularly: keep it clear of stored items, and look for leaks, corrosion, or damage to visible pipes. Make sure the intake and exhaust openings remain unobstructed. Do not remove the cover or adjust gas or electrical connections unless the manual identifies a safe user task.
Some models have an inlet water filter that the owner can inspect or clean. Follow the manual’s directions, including how to shut off the water before removing it. If you are unsure how to do this, ask a qualified technician. Keep a note of completed checks and service dates so you can track recurring problems and stay on schedule.
Why Mineral Buildup Matters
Hard water contains minerals such as calcium and magnesium. As water heats, some of those minerals can settle inside the heat exchanger and form scale. Over time, scale can restrict water flow and reduce heat transfer, making the unit work harder to deliver hot water. The pace of buildup depends on the water quality, how much hot water the household uses, and the heater’s design.
Descaling, often called flushing, helps remove mineral deposits from the unit. Follow the manufacturer’s instructions for the correct method and service interval; some homeowners prefer to have a technician handle the process. If your home has hard water or scale appears frequently, ask a qualified professional whether water treatment or more frequent maintenance is appropriate. Avoid using a cleaning solution that the manufacturer has not approved.
Watch for Signs of Trouble
Pay attention to changes in hot-water performance. Water that takes longer to heat, fluctuates in temperature, or runs out sooner than usual may point to scale, a clogged filter, or another issue. Reduced flow at multiple hot-water fixtures can also be a clue. Note when the problem occurs and whether it affects one fixture or the whole home; those details can help a technician narrow down the cause.
Check the unit’s display for an error code and look it up in the owner’s manual. A code can identify a condition that needs attention, but it does not always explain the root cause. Call for service if the same code returns, the unit shuts down repeatedly, or you notice a leak, unusual noise, or visible corrosion. If you smell gas, leave the area and contact your gas utility or emergency services from a safe location.
Know When to Call a Technician
A qualified technician can inspect internal components, confirm the cause of an error, and perform maintenance that requires opening the unit or handling gas and electrical connections. Schedule service when the heater’s performance changes, routine cleaning does not resolve a problem, or the manual calls for professional maintenance. For a newer installation, check whether service requirements affect the warranty.
Before booking, write down the model number, any displayed error code, when the symptoms began, and what checks you have already completed. Share whether the issue affects every fixture or only one. Clear access to the heater and its shutoff valves so the technician can inspect the installation safely.
Regular visual checks, proper filter care, and descaling at the interval recommended for your unit can help prevent avoidable problems. Follow the manual, and do not attempt repairs involving gas, wiring, or internal parts. If your tankless water heater shows repeated errors or inconsistent performance, contact Willamette Tankless to discuss service options.