Flushing a Tankless Water Heater: Step-by-Step Guide

Welcome to Best Service Plumber's comprehensive guide on flushing a tankless water heater. Regular maintenance is essential to keep your tankless water heater running efficiently and prolong its lifespan. Flushing your tankless water heater removes mineral deposits and sediment that can accumulate over time, ensuring optimal performance and reducing the risk of breakdowns. Follow our step-by-step instructions below to successfully flush your tankless water heater.

Why Flush a Tankless Water Heater?

A tankless water heater is a great investment for any home. It offers energy efficiency and a continuous supply of hot water. However, like any appliance, it requires regular maintenance to maintain its efficiency levels. Flushing a tankless water heater is crucial because:

• Mineral deposits can build up in the heat exchanger, impairing its ability to efficiently heat the water.
• Sediment and debris can accumulate, leading to clogs and reduced water flow.
• Corrosion can occur due to mineral buildup, potentially causing leaks or other malfunctions.

By flushing your tankless water heater at least once a year, you can prevent these issues and ensure a longer lifespan for your unit.

Step 1: Turn Off the Power and Gas Supply

Prior to flushing your tankless water heater, it is important to ensure the power and gas supply are turned off. This step will prevent any accidents or damage during the process. Here's how:

1. Locate the main power switch on your tankless water heater and turn it off.
2. Next, locate the gas supply valve and turn it to the "Off" position. If you have an electric tankless water heater, you can skip this step.

Always prioritize safety when performing any maintenance on your tankless water heater.

Step 2: Gather the Necessary Tools and Materials

Before beginning the flushing process, gather the following tools and materials:

• Bucket or drain pan
• Garden hose
• White vinegar or a descaling solution recommended by the manufacturer
• Wrench or pliers to disconnect water lines (if necessary)

Having these items readily available will make the process smoother and more efficient.

Step 3: Locate the Cold Water Inlet and Hot Water Outlet Valves

Find the cold water inlet and hot water outlet valves on your tankless water heater. These valves allow water to flow in and out of the heater during the flushing process. The valves are typically labeled "Cold" and "Hot." You may need to use a wrench or pliers to open or close these valves.

Step 4: Connect the Garden Hose

Connect one end of the garden hose to the hot water outlet valve and the other end to a nearby drain or outside area where the water can safely discharge. Ensure a secure connection to avoid any leaks or spills.

Step 5: Turn on the Cold Water Inlet Valve

With the garden hose securely connected, slowly open the cold water inlet valve. This valve allows fresh water to flow into the tankless water heater and flush out any accumulated debris or mineral deposits.

Step 6: Flushing the Water Heater

Once the cold water inlet valve is open, you can begin flushing the water heater. Follow these steps:

1. Open the hot water outlet valve gradually.
2. Let the water flow through the system for around 20-30 minutes or as recommended by the manufacturer. Flushing times may vary depending on the amount of sediment buildup.
3. Monitor the water flowing through the garden hose. If you notice excessively dirty or discolored water, you may need to repeat the flushing process until clear water comes out.
4. After flushing, close the hot water outlet valve and then the cold water inlet valve.

Remember to be patient during the process and let the water flow until it runs clear.

Step 7: Descaling the Heat Exchanger (If Required)

In some cases, mineral deposits may have accumulated in the heat exchanger of your tankless water heater. If your manufacturer recommends descaling, follow these steps:

1. Mix a solution of white vinegar and water (equal parts) or use a descaling solution recommended by the manufacturer.
2. Connect the garden hose to the hot water outlet valve.
3. Submerge the other end of the hose into a container filled with the descaling solution.
4. Open the cold water inlet valve and let the solution circulate through the system for the recommended time (usually one hour).
5. After descaling, close the hot water outlet valve, remove the garden hose, and dispose of the descaling solution properly.

Make sure to thoroughly rinse the tankless water heater before proceeding to the next step.

Step 8: Reconnect the Water Lines and Restore Power Supply

Now that the flushing and descaling process is complete, it's time to reconnect the water lines and restore the power supply:

1. If you have disconnected any water lines, reconnect them using a wrench or pliers.
2. Ensure all valves are properly closed except for the cold water inlet.
3. Turn on the power supply to the tankless water heater.
4. Check for any leaks or drips around the connections and address them if necessary.

Congratulations! You have successfully flushed your tankless water heater and restored it to optimal performance.

Conclusion

Regularly flushing your tankless water heater is an essential maintenance task that should not be overlooked. By following our step-by-step guide, you can ensure the longevity and efficiency of your tankless water heater, saving you money on energy costs and avoiding inconvenient breakdowns. Remember to consult your manufacturer's instructions for specific guidelines and recommended flushing intervals.

For professional water heater installation and repair services, rely on Best Service Plumber. Our skilled technicians are well-versed in all aspects of plumbing and are ready to assist you with all your plumbing needs. Contact us today for reliable and efficient service.