Do I Need a Tankless Water Heater Flush Kit?

If you already own a tankless water heater, or you’re considering purchasing one, you’re probably wondering how often you’re supposed to flush it. Most manufacturers and plumbers recommend flushing your tankless water heater at least once a year, on top of getting professional maintenance performed regularly. Many factors can affect how often it needs to be done, especially the hardness of your water and the frequency of use.

In this article, you’ll learn what happens if you don’t flush your tankless water heater, what you should use to flush it, and how much it could cost to flush it. It’s important to note that more complicated maintenance of your water heater should only be performed by a professional.

Features of the Tankless Water Heater Cleaning Kit

It’s worth it to invest in a tankless water heater cleaning kit to extend the longevity of your appliance.

What is included in the kit?

The best tankless water heater cleaning kit will include a five-gallon flush tank, a submersible pump, five-foot hoses, and a complete how-to guide for less than $200. Purchasing a kit will allow you to perform this maintenance yourself, instead of paying a professional to complete it. After that one-time purchase of the kit, you’ll only be required to buy more descaling solution as needed.

Is there a specific kit designed for my brand of water heater?

One of the best things about tankless water heater cleaning kits is that they work on all tankless water heater models. You will not need to purchase a separate flush kit for different types of water heaters, whether yours is gas or electric.

Is it safe to use a cleaning kit?

Kits are safe for septic systems, sewers, and potable water systems. Using a kit is completely safe, and performing this regular maintenance of your tankless heater system will help it perform better, too.

How a Tankless Water Heater Cleaning Kit Works

The actual flushing involves pumping a vinegar or other descaling solution through the unit. This allows the solution to remove carbonates, sulfates, phosphates, rust, oxides, and other mineral deposits from the inner components. The basic steps to flushing your tankless water heater are:

  1. Hook up the hoses. One to the hot water side (where flushed solution will exit), and one to the cold water side (through which water to descale will be supplied).
  2. Attach the pump to the supply hose on the cold side. The pump has a small motor that drives the water through the unit. Submerse the attached pump in the bucket of cleaning solution (follow manufacturer guidelines for solution mixing).
  3. Run the hose from the hot side into the tank to complete the flushing loop. Open the valves, then plug in the pump. The pump will begin to operate, flushing the tankless water heater by cycling it through the system for 30–45 minutes.
  4. Run cold water for a couple of minutes. Turn off the isolation valve on the cold water side, and turn on the cold water. This will send a jet stream of water (no cleaning solution) through the system to loosen any remaining debris. Disconnect the hoses.
  5. Pull out the filter. Blow out any remaining debris in the filter or run it under a faucet to wash away any buildup. Return the filter.
  6. Replace the components, turn the gas back on, and plug in the unit.

Things to Consider Before Buying a Tankless Water Heater Kit

There are a few things to consider before buying a flushing kit, which could save you more money.

  • Assemble your own kit: This is potentially more cost-effective. You can purchase the necessary components separately. You’ll need flushing fluid, a pump, a hose kit, and any five-gallon bucket.
  • Buy a ready-made kit: For a higher cost, you can have the peace of mind that your kit has everything you’ll need.
  • Read customer reviews. If you’re buying components online, be sure to read customer reviews of the different parts before making a purchase to ensure what you’re considering is high quality. Remember, you’ll need to use these parts to flush the unit about once a year.
  • Consider hiring a professional: You can hire out the task of flushing a water heater, if you don’t feel comfortable doing it yourself. Just call a qualified plumber or other technician to perform the work. Don’t forget, any additional maintenance on your water heater should ONLY be performed by a professional to keep you safe.

Learn more about propane-powered water heaters here.