Frequently Asked Questions About Descale Tankless Water Heater
If your unit has isolation valves with service ports already installed, a DIY descaling is possible with a pump, bucket, and white vinegar. However, our service also includes filter cleaning, burner inspection, flame sensor check, and a full system test that DIY typically skips. If your unit does not have isolation valves, we can install them during the first service visit.
Yes. Food-grade white vinegar is the manufacturer-recommended descaling solution for most tankless brands, including Rinnai, Navien, and Noritz. The acetic acid dissolves calcium carbonate without damaging copper or stainless steel heat exchanger surfaces. We never use harsh chemical descalers that could corrode internal components.
Error codes related to overheating, restricted flow, or scale detection (like Rinnai Error LC or Navien Error 003E) are often resolved by descaling. Ignition or flame failure codes may also clear after descaling if scale was causing overheating that triggered a safety shutdown. Our plumber diagnoses the specific cause before recommending descaling alone or additional repairs.
If the heat exchanger is cracked, severely corroded, or damaged beyond what descaling can restore, we will explain the situation honestly and present repair or replacement options. A failed heat exchanger usually means replacement is the better investment, especially on older units.

