How To Properly Flush A Tankless Water Heater! #plumbing #rinnai

Introduction

This tutorial provides a comprehensive guide on how to properly flush a tankless water heater, specifically a Rinnai model. Regular maintenance, such as flushing, is essential to prolong the life of your water heater and ensure optimal performance. This process is applicable to any tankless water heater equipped with flush valves.

Step 1: Disconnect Power and Water Supply

• Locate the power source behind the refrigerator and disconnect the power to the water heater.
• Shut off the water supply to the heater.

Step 2: Prepare for Flushing

• Remove the caps from the flush valves on the tankless heater.
• Use stainless or plastic washing machine hoses to prevent corrosion. Avoid steel hoses.

Step 3: Connect Hoses

• Attach one hose with connectors on both ends to the cold side flush valve.
• Connect the other hose (with one open end) to the hot side flush valve.
• Place the other ends of the hoses into an empty bucket to catch the draining water.

Step 4: Drain the Water Heater

• Turn the valve to the "on" position for the flush line, allowing water to drain into the bucket.
• After draining, remove the small cap from the filter screen located near the cold flush valve. Expect some residual water to spill out.

Step 5: Clean the Filter Screen

• Inspect the filter screen for sediment build-up.
• Clean the screen gently to avoid damage and reattach it, ensuring it is snug but not overly tight.

Step 6: Prepare the Descaling Solution

• Use a descaling solution, such as Qwikproducts descaler, diluted with five parts water.
• Pour the solution into the bucket.

Step 7: Set Up the Pump

• Utilize a submersible pump to circulate the solution.
• Connect the pump to the cold flush side using a stainless hose.

Step 8: Start the Flushing Process

• Plug in the pump to begin the circulation, allowing the solution to flow through the heater for approximately 45 minutes to an hour.
• Monitor the color of the solution; it should change to indicate the need for more descaling solution.

Step 9: Inspect Internal Components

• While the solution is circulating, remove the cover of the heater to access the igniter and heat exchanger.
• Clean both components as needed, ensuring no excessive build-up is present.

Step 10: Drain and Rinse

• After the flushing period, unplug the pump and allow the solution to drain completely.
• Open the hot side valve and close the cold side valve to flush remaining solution from the heater using fresh water.

Step 11: Final Checks

• Repeat the inspection of the filter screen and clean it again if necessary.
• Close the cold flush valve and open the hot flush valve to flush any residual chemicals from the system.

Step 12: Restore Power and Water Supply

• Reconnect the power and water supply to the heater.
• Check for proper operation by running hot water to ensure everything is functioning correctly.

Conclusion

Flushing your tankless water heater is a straightforward process that enhances its efficiency and prolongs its life. Regular maintenance, including cleaning the filter and inspecting internal components, is crucial. Follow these steps periodically to ensure optimal performance from your water heater.