Hackensack – October 13, 2026 -- Tankless water heaters need yearly care, and skipping it can lead to costly repairs, according to a HelloNation article featuring plumbing and HVAC expert Scott Wickersheim of Wickersheim & Sons in Hackensack, New Jersey.
Hard water builds up inside the heat exchanger
Many homeowners assume a tankless unit runs on its own indefinitely once it is installed. The article says that does not match reality. In homes with hard or well water, calcium and magnesium accumulate inside the heat exchanger, restricting water flow and forcing the system to work harder to heat the same amount of water.
Ignored buildup can end in lockouts or total failure
Left unchecked, the buildup can trigger high temperature lockouts, sudden drops in water pressure, or complete system failure. These problems rarely arrive without warning, because minor symptoms tend to show up first. The article lists inconsistent hot water temperatures, longer waits for hot water, and error codes on the unit's control panel.
If those signs are ignored, buildup can permanently damage the heat exchanger, one of the most expensive parts to replace in the unit. Routine maintenance, by contrast, helps the system heat water faster and use less energy to reach the desired temperature.
An annual flush is the main defense
The article describes annual flushing as the most effective protection against sediment. A professional plumber circulates a descaling solution through the system to clear out accumulated minerals. Homes with softer water still benefit from an annual check, even if flushing is needed less often.
For homes with hard water, the article notes that plumbing and HVAC experts often recommend a whole home water softener to protect the heater and other fixtures. It also advises checking the unit's air intake and exhaust vents periodically, since debris or insects can block them and interfere with safe operation.
Spring and fall appointments can mean shorter waits
Scheduling the service in the same month each year makes it easier to remember. Spring and fall are popular choices because demand for plumbing services tends to be lower, which can shorten wait times.
New homeowners who inherit a tankless system should request maintenance records or schedule a flush soon after moving in. The article concludes that a small amount of yearly care can prevent major expenses and extend the unit's life for many years.