Tankless Geek topic guide
Hard Water and Tankless Water Heaters
Mineral scale can restrict flow and heat transfer, but treatment and service choices should follow measured water quality and the manufacturer manual.
Updated
Direct answer
Test hardness, review the model's water-quality limits, install treatment where justified, and keep a service record. Do not assume a scale inhibitor is equivalent to a water softener.
Measure before treating
A laboratory or utility report provides a defensible starting point. Hardness, sediment and other chemistry can require different responses.
Warranty conditions
Some manufacturers exclude damage associated with water outside stated limits or missed maintenance. Read the current warranty before installation.
Questions people ask
Will a tankless heater remove hardness?
No. A water heater does not soften water. Treatment is a separate system decision.