Does Water Softening Promote Corrosion of a Hot Water Heater?

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Does Water Softening Promote Corrosion of a Hot Water Heater?

There is some information going around that isn’t completely correct, and I’d like to take a little time to talk about it. It’s the question that’s in the title of this blog, referencing water softening promoting corrosion in a hot water heater.

A short chemistry lesson

The place to start is with what a water softener does. Nearly all of them use salt (sodium) which when added to hard water starts a chemical reaction. The sodium ions are exchanged with the calcium and magnesium ions that give hard water its mineral content. The softened water now contains more sodium (salt).

What happens in the water heater

In electric water heaters, a tiny fraction of the current can leak into the water and start another chemical reaction that causes corrosion. It is true that the presence of sodium in soft water enhances this process and increases the corrosion. But as Paul Harvey used to say, “Now the rest of the story.”

The sacrificial lamb

All modern water heaters include something called an anode rod. It’s made of a material that attracts the electrons causing the corrosion. It is the sacrificial lamb that keeps the corrosion from eating away the rest of the water heater or the pipes in your Waterford, MI house. The soft water will cause the anode rod to corrode more rapidly but it will protect the water heater until it is eaten away. To be clear, the sacrificial anode rod can be easily replaced as a part of regular water heater maintenance.

Pros and cons

Water conditioning is like a lot of decisions: There is a cost/benefit analysis that needs to be made. A softener WILL reduce mineral buildup inside pipes & plumbing fixtures. It will also reduce sediment buildup inside the water heater making it more efficient. But the salt will increase the corrosion rate of the anode rod and will corrode the water heater more quickly if the anode rod is not replaced on a regular basis.

Kotz is here to help

If you have any more questions about water conditioning and water heaters in your Waterford, MI home, don’t hesitate to call Kotz Heating, Cooling & Plumbing. Be sure to like and follow us on Facebook and Twitter.