Ask Any Hour - Is a Water Softener Compatible with a Tankless Water Heater?


Dear Any Hour,

I just read all about tanked vs tankless water heaters.

There was no mention of water softeners. Is it possible to use a water softener and a tankless water heater?


Gaye Lynn P

Ask Any Hour - is water softener compatible with tankless water heater

This is a great question! In fact, a number of our customers have asked our plumbers similar questions about how water softeners work with their water heaters. So, to give a comprehensive answer, we’ll talk about both tanked and tankless systems to answer both Gaye’s question and others we’ve received! Since Gaye’s question directly relates to tankless water heaters, let’s start there.


Tankless Water Heaters

For customers who either already have a tankless water heater or are considering switching to tankless, a water softener is a great idea. Because it helps protect your water heater, we will actually recommend a water softener with all tankless installs we do!

Here’s how it works. Tankless water heaters are relatively low-maintenance except that about once per year manufacturers recommend flushing a descaling solution through the system to get rid of any hard water buildup on the heat exchangers. Hard water buildup can decrease the efficiency of your tankless water heater and also corrode and break down the components inside. With soft water, your tankless system is nearly maintenance-free, as soft water prevents the buildup of hard water. So, while it's always a great idea to check on your water heater yearly, with a softener, you likely won't have to flush it.

If customers don't already have a water softener and wish to install one, we can install a water softener at the same time as the water heater. However, if customers don’t wish to add a softener, there are still many benefits to tankless water heater ownership, including endless hot water and higher efficiency. Owners would just need to make sure and stay on top of their yearly maintenance flush.

To learn more about tankless water heaters, click here:


Standard (Tanked) Water Heaters

Because Utah has such hard water, many water softener companies will recommend water softeners to homeowners, arguing that using them in conjunction with a standard, tanked water heater will take the wear and tear off the water heater. In actuality, it’s a little more complex. Water softeners can help your water heater in some ways and hurt it in others.

Water hardness is based on the amount of calcium and magnesium it contains. Water softeners remove the calcium and magnesium from the water through a process called ion exchange. Essentially, the water softener’s mineral tank is filled with polystyrene beads that hold a negative charge, which attracts the positively-charged calcium and magnesium ions. Positively charged sodium (salt) ions (or its more expensive counterpart, potassium chloride,) are then flushed through the system, collecting the calcium and magnesium and sending it down the drain. That’s what the bags of salt and brine tanks are for in water softening systems. This is also what gives soft water its slightly salty taste.

So, while it’s true that a water softener will prevent a lot of calcium buildup inside the water heater, it will corrode the inside of your water heater tank at a much faster rate. The softened water contains so much sodium that sits in your tank, eating at the materials inside until it actually starts to break down the steel walls of the tank. So, while you may not need to flush your water heater as often to get rid of the hard water sediment, you will still need to keep up with regular maintenance, paying particular attention to a part called the anode rod.

The anode rod, sometimes called the sacrificial anode rod, is the part built into your water heater to help withstand corrosion. This rod is crucial to the prevention of water heater failure. The anode rod is designed to attract the corrosive material in your water so that it will corrode before your water heater will. This is why it’s called sacrificial; its demise means your tank is spared.

If you decide to install a water softening system, you might want to check your anode rod at least once per year and replace it as needed. Otherwise, if your tank corrodes, it could lead to rusting, leaks, ruptures, and other failures.

At the end of the day, there’s no such thing as a solution for your home that doesn’t require regular maintenance. It’s the only way to keep your systems happy and healthy--with or without a water softener!

For more information on water heater maintenance, you can do yourself, click here.



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Author: Amber Smith-Johnson
Copyright © 2019 by Any Hour Services


Aug 4th 2019

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