How a Water Softener Can Impact Your Water Heater Efficiency?

Having a water softener can provide many benefits, from extending the lifespan of your plumbing fixtures to improving the taste and feel of your drinking water. One area that often gets overlooked is how a water softener can affect the performance and lifespan of your water heater.

In this article, we’ll explore the science behind water softening, how it impacts the efficiency of your water heater, and what can be done to optimize your water heating system.

So, let’s dive in and explore the positive and negative effects that a water softener can have on your water heater.

Key points:

  • A water softener can help to reduce the number of mineral deposits that accumulate in your pipes and hot-water tank. This helps to improve the efficiency and lifespan of your system, as well as reduce energy costs associated with heating hard water.
  • However, soft water causes corrosive damage to the water heater anode rod, reducing its effectiveness.
  • As soon as corrosion starts occurring, it’s important to replace the anode immediately in order to prevent long-term damage or even failure of your hot water heater tank.
  • Salt-based water softeners are the best option for use with water heaters.

The Pros and Cons of Having a Water Heater with Water Softener

A water softener can provide many benefits to water heating systems but also has some potential drawbacks. It is important to understand both sides of the equation before investing in this type of system.


  • A water softener helps to protect your water heater from the harmful effects of hard water, which can cause scale buildup that can lead to costly repairs or a complete water heater replacement.
  • Softened water is much more efficient for heating, as it doesn’t require as much energy to heat. This means that you’ll be able to save money on your energy bill in the long run.
  • The softer water also makes showering, washing dishes, and doing laundry more comfortable since there is no residue left behind on skin or fabrics when compared to hard tap water.


  • Soft water corrodes the anode in a water heater significantly faster than hard water does.

Naturally Soft Water Vs. Salt-Softened Water, Which is Best for Water Heaters?

Salt-based water softeners or salt-softened water is the best to use with water heaters.

Naturally soft water has lower pH and Total Dissolved Solids (TDS) levels than untreated water. The lower pH can help reduce the formation of scale buildup in the pipes which can reduce the efficiency of your water heater. However, the lower pH also increases the water’s corrosive properties which can cause damage to the anode rod used to protect the heater from corrosion.

To combat this, you should opt to soften your water through an ion exchange system. This salt-based process involves exchanging positive ions from the water with a salt solution, which in turn decreases the water’s pH and hardness while increasing its alkalinity. This reduces the corrosive properties of the water while still providing adequate protection against scale buildup.

While salt-softened water can bring many benefits, it can raise your budget slightly due to the cost of the salt used in the process as well as the energy required to operate the system.

Tips for Improving Water Heater Efficiency

Here are a few tips to get the most out of your water heater:

  • Insulate hot water pipes: Insulating the hot water pipes can help prevent heat from escaping and reduce energy consumption.
  • Check the tank for sediment: Sediment can build up in the tank over time, which can reduce its efficiency. You can check the tank for sediment and remove it if needed.
  • Install a timer: Installing a timer on your water heater can help you to better control the temperature of your water and save you energy.
  • Lower the thermostat setting: One of the simplest ways to improve your water heater efficiency is to lower the thermostat setting. This will reduce the amount of energy needed to heat the water and save you money.
  • Replace old parts: If you have an old water heater, it’s likely not running as efficiently as it should. Replacing old parts, such as heating elements, thermostats, and insulation, can help improve efficiency.
  • Perform routine maintenance: Regular maintenance is important for any appliance. If you take care of your water heater, it can last longer and run more efficiently.
  • Consider a tankless water heater: Tankless water heaters are becoming increasingly popular for their energy efficiency. If you want to save even more money on your utility bills, you should consider installing a tankless water heater.

Frequently Asked Questions

Is soft water bad for water heaters?

No, soft water is not bad for water heaters. It helps reduce scale buildup, which results in the high efficiency of the water heater. However, the answer to whether soft water is good or bad for your water heater depends on the type of softening system used. Naturally softened water, which is low in pH level and total dissolved solids (TDS), can be corrosive and damaging to a hot water heater over time. On the other hand, salt-softened water has higher pH and TDS levels, making it less corrosive.

How does the anode rod protect the water heater from corrosive damage?

The sacrificial anode rod in residential hot water heaters is made of magnesium or aluminum and its purpose is to attract corrosion and protect the steel tank from rusting out. The magnesium or aluminum anodes will naturally corrode over time as they give up electrons to balance out charge differences between them and other metals in contact with the same solution, such as steel.

Can you install a water softener with a tankless water heater?

Yes, using a water softener with a tankless water heater is a great way to prevent mineral buildup and reduce energy costs. Tankless water heaters are more efficient than traditional hot-water storage tanks, but they require regular maintenance to ensure they remain efficient. Installing a water softener in combination with your tankless water heater can help extend its lifespan while reducing the energy costs associated with heating hard water.