Benjamin Franklin Plumbing team with service van

Tankless Water Heater Flush and Descaling

Descaling removes the mineral build-up that hard water leaves inside a tankless water heater, which helps maintain its efficiency and prevents overheating. If your tankless water heater gives inconsistent temperatures, shuts down mid-shower, shows an error code or will not ignite, it usually needs a diagnosis and repair rather than replacement. Call when hot water becomes unreliable or when routine maintenance is due.

Table of Contents

Why tankless water heaters need descaling in the Valley
What tankless maintenance includes
Tank water heaters need flushing too
Hard water at the source
Book a visit

Why tankless water heaters need descaling in the Valley

Hard water is common in Phoenix: water picks up calcium and magnesium as it moves through minerals in the ground. When hard water is heated, minerals form a hard layer on heating parts. This scale reduces efficiency, so the heater needs more energy to heat water.

What tankless maintenance includes

Regular maintenance includes descaling to prevent mineral buildup and checking the system for any potential issues.

Descaling removes the mineral build-up that hard water leaves behind. It helps maintain the heater's efficiency and prevents overheating.
The system's air and water filters should be cleaned or replaced regularly, because clogged filters restrict flow and make the heater work harder.
A professional check-up also looks for gas or water leaks and checks the electrical connections.

If the unit gives inconsistent temperatures, shuts down mid-shower, shows an error code or will not ignite, see tankless water heater repair.

Tank water heaters need flushing too

A water heater flush removes sediment and buildup from a tank water heater. See water heater repair.

Hard water at the source

If a water test shows hard water, a water softener reduces the minerals in your water, which cuts scale buildup and helps protect water-based appliances. See water treatment.

Book a visit

Book online or call 602-282-5007. We schedule appointments from 6 AM to 8 PM every day, and our call center answers any time. A service call is $79, and it is waived when we do the work. With StraightForward Pricing® you see the price before any work starts.

If there's any delay, it's you we pay!® We pay you $5 for every minute we're late, up to a $300 maximum.

Frequently asked questions

What does descaling a tankless water heater do?

Descaling removes the mineral build-up that hard water leaves inside the heater. It helps maintain the heater's efficiency and prevents overheating.

How do I know my tankless water heater needs service?

Call when hot water becomes unreliable or when routine maintenance is due. Inconsistent temperatures, shutting down mid-shower, an error code or a unit that will not ignite usually mean it needs a diagnosis.

Do tank water heaters need flushing?

Yes. A water heater flush removes sediment and buildup from a tank water heater.

How much does tankless water heater service cost?

The cost depends on the root cause, the model of your unit and whether parts, descaling or a full replacement is needed. A service call is $79, and it is waived when we do the work. With StraightForward Pricing® you see the price before any work starts.