Hard Water and Water Heaters Do Not Mix

Written by David Heffner of Heffner Plumbing
Updated September 16, 2015
Water softener and water heater
Water softeners play an important role in protecting your water heater. (Photo by Summer Galyan)

An Indianapolis plumber gives advice on hard water and water heaters.

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The one thing that will lower the efficiency of a water heater and drive up your operating costs is hard water.

In a gas water heater, the lime will settle to the bottom of the tank and create a layer that heat has to pass through to then heat the water. This layer of lime grows over time, reducing efficiency, increasing costs through longer heating cycles and eventually reducing the capacity of the water heater tank.

In electric water heaters, lime will build up on the heating elements as well as settling to the bottom of the tank. Again, reduced efficiency, increased operating costs and reduced capacity will happen with an electric water heater on hard water.

Draining a water heater does not effectively remove lime that has built up in a water heater tank. Flushing a water heater means leaving the valve on that is feeding the cold water into the tank. Simply connect a garden hose to the drain valve at the bottom of the water heater and then open this valve up. The force of the incoming water will help to remove more of the lime then by just draining the tank.

Water heaters that are on hard water probably need to be flushed every three months. This time frame may vary plus or minus depending on the hardness of the water.

Water heaters that are operating on soft water really don't need to be flushed. For general purposes however, once a year would be sufficient.

David Heffner is a licensed plumbing contractor in the state of Indiana and is bonded and insured. Heffner Plumbing is a highly rated company with Angie’s List and has received the Super Service Award every year since 2004. Heffner received the 2009 Contractor of the Year Award by the Greater Indianapolis Plumbing-Heating-Cooling Contractors (GIPHCC).

As of Jan. 20, 2012, this service provider was highly rated on Angie’s List. Ratings are subject to change based on consumer feedback, so check AngiesList.com for the most up-to-date reviews. The views expressed by this author do not necessarily reflect those of Angie’s List.

Have you had problems with hard water? Tell us about it in the comments below.

Editor's note: This is an updated version of an article originally posted on Jan. 20, 2012. 

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