4 Best Water Softener to use with Tankless Water Heaters

Winter season brings the need for hot water. Many of the fellow Americans prefer tankless water heaters because of their small size, instant water heating abilities, and low power consumption. Some of the high-quality tankless water heaters can even last longer than a tank based water heater. However, one thing can really influence the life and working of tankless water heaters in the long run, and that is water hardness. A majority of people in the US have to face hard water problems.

How to deal with this problem?

The best way to get rid of the hard water problem for your tankless water heater is by installing a water softener. When it comes to tankless water heaters, the effects of hard water are not visible instantly or in a couple of months. The scale may get deposited after 2-3 years, depending upon the level of hardness in your water. The reason is that a tankless water heater does not store water; hence the scale does not get deposited instantly as in the case of a tank heater. Despite all of this, you still need to be prepared to deal with this problem. We don’t want you to end up with a faulty water heater after a couple of years and regret. It is better to find a solution at the right time and it is never late to protect your costly and valuable appliances.

Which softener is best for a tankless water heater?

Experts advise that you use a specialized water softener with your tankless water heater. A traditional salt-based water softener can also be used with your water heater. However, using a salt-less or electric/magnetic system is better, because salts can react with the anode rods inside the heater. The anodes are installed to protect the corrosion of the internal metallic lining of the water heater. The anode rods are made of metals such as magnesium, aluminum, or zinc. Water softened by a salt-based water softener has high amounts of sodium or potassium. These salts can react with the metallic surface of the anode rod and can significantly reduce its lifetime. As a result, the working efficiency of your heater can go down, and ultimately it stops working.

Where to buy the best softener for a tankless water heater?

Hence, it is better to get a no-salt softener for your tankless water heater. Finding a specific softener for your water heater can be a very challenging task. Not all people are aware of the technical specifications and which model is best for them. Not all know the ins and outs of a water softener and how to select the most appropriate one. We are here to solve this problem for you. We have selected the best ones and reviewed them for you. In this guide, you will find the best softeners for your heaters, and a buying guide to help you make the best purchase.

Please note that we have only included the softeners to be used with water heaters. If you are looking to find softeners for other purposes, you can read our other guides on softeners.

Let’s begin

Best Water Softener for Tankless Water Heater

	Top Picks (Comparison)
	Editor's Choice3M Aqua-Pure Whole House Scale Inhibition Inline Water System 25-125 PSI water pressure Ideal for Tankless, tank heaters, and boilers stainless steel body	LATEST PRICE →
	Magnetic Water Softener & Conditioner 10 years warranty Best for RVs, boats, and trailers Hassle-free installation	LATEST PRICE →
	Clearwave 46100000 Field CW-125 Easy and hassle-free installation Free maintenance No interruption in water flow	LATEST PRICE →
	Tankless Water Heater Filter Flow rate 14 GPM Best for scale prevention 125 PSI water pressre	LATEST PRICE →

1. 3M Aqua-Pure Whole House Scale Inhibition Inline Water System AP430SS, Helps Prevent Scale Build Up On Hot Water Heaters and Boilers

At the top of our list is a well-trusted water softener, build especially to protect and enhance the life and efficiency of your water heaters. It is a versatile product and can be used with tankless, tank heaters, and boilers. You can use it with propane-powered and electric-powered heaters without any worries. By preventing the scale buildup, it ensures a long life of your heater, plumbing pipes, appliances, faucets, and showerheads. When the water entering your heater is not developing any scale on it, it will automatically ensure a better working efficiency.

The softener has the capacity to maintain a high flow rate and will not hinder the natural speed of the water at your home. It has the ability to manage flow rates of up to 10 GPM without any issues and can handle an incoming pressure of 25-125 PSI, and an operating temperature of 40-100F.

The stainless steel body gives the softener a long life and keeps it corrosion and rust-free for a very long time. You must install it on cold water pipes leading towards the water heater, and it comes with ¾ NPT connections to allow easy connections with different sizes of plumbing. The softener bags certification from NSF against standard 42 for structural and material integrity.

Our Opinion and Verdict:

2. Magnetic Water Softener & Conditioner

The next softener for tankless water heaters on our list is quite an innovative one. It uses magnetic technology to crystallize the hardness-causing elements like calcium and magnesium. We are amazed by its performance and the price at which it is being sold. If you are running tight on a budget and want a quality softener for your tankless water heater, you need to look no further as you have just found the best one.

Made out of solid steel, it is easy to install and can be installed in just half an hour without any big tools or professional help. All you have to do is install it before the cold water enters your heater and you are good to go.

It comes with a 10-year warranty; you can also use this conditioner in your RVs, boats, and trailers without any problems. The small size makes it perfect for all users.

Our Opinion and Verdict:

3. Clearwave 46100000 Field CW-125, WHITE

This softener is more of a water conditioner. It uses electric power to crystallize calcium and magnesium in water, so they don’t stick to any surface they travel on. You can protect your hot and cold water plumbing lines with this conditioner, and it shows excellent results as well.

The conditioner can also be used for your whole house purpose if you are a small family. It works well on copper, PVC, and stainless steel pipes. For other pipes, the results are not that effective. The installation process is easy and won’t consume more than 30 minutes. Make sure you have an electric socket near the point of installation. All you have to do is wrap the wires around the water pipes, plugin and turn it on. It will do the rest for you. The conditioner will not interfere with your flow rate as water will not pass through it.

Our Opinion and Verdict:

4. Tankless Water Heater Filter, KleenWater KW2520SCALEX Tankless Hot Water Filter System, Polyphosphate Filter for Scale Prevention

Another option to protect your tankless water heater from the massive impacts of hard water comes from KleenWater. It offers you a large clear housing and a polyphosphate cartridge to remove the scale causing elements in the incoming water. When the water leaves the filter, it is fit to be used with a water heater (tankless or with tank). The polyphosphate cartridge is made from food-grade materials, so no health concerns are being involved here.

The filter can handle a maximum working pressure of 125 PSI and a temperature of 120F. It can provide you with a maximum flow rate of 14 GPM. If the incoming water has a higher pressure than 14 GPM, the softener may reduce the outgoing flow rate as it cannot manage high flow rates.

Everything needed to install the system is included in the box; you don’t have to buy anything separately. All you need to do is drill a couple of holes, put the bracket in, hang the filter, make the connections, and you are good to go. The whole process will take 2-3 hours.

Our Opinion and Verdict:

Buying Guide

Type

You have to select the type of softener you want for your water heater. You can buy an electric water conditioner, which is costly but effective. A magnetic softener is inexpensive but does not show the same results as an electric one. You can also go for a cartridge-based water softener for your heater. It is the best one as it is economical, can be used at almost all the setups, and gives excellent results.

Water Demand

You should look at the water demand of your home as well. We don’t want you to end up buying a smaller unit while you need a big one. Make sure the flow rate, working efficiency, and capacity match with your needs.

Budget

Many people consider a water softener for a water heater is not a necessity. Yes, it may be true, but only for homes with a whole house water filter installed. If it is a salt-based water softener, it can impact your water heater’s life and work. It is recommended to spend a little more on water softener for your heater and save yourself a lot of money in the long run.

Installation Space

Make sure you have ample space at the place where you intend to install the softener. All the water softeners reviewed above are compact and does not occupy much space. However, it is still better to do a little survey and make sure there is enough space for easy installation without any alterations.

Final Thoughts