Can I use a vinegar solution to clean the heat exchanger on the Noritz NR66 OD, and how is this done?

Cleaning the heat exchanger on a tankless water heater like the Noritz NR66 OD with a vinegar solution is a common maintenance task to remove mineral deposits and scale buildup. Vinegar is an effective and environmentally friendly descaling agent for this purpose. Here's how you can clean the heat exchanger with a vinegar solution:

Materials You'll Need:
* White Distilled Vinegar: You'll need a sufficient amount of white distilled vinegar to create a descaling solution. The exact quantity will depend on the severity of the scale buildup and the size of the heat exchanger.
* Garden Hose: You'll need a garden hose and access to a water source.
* Bucket: To mix the descaling solution.
* Submersible Pump (optional): A submersible pump can be used to circulate the vinegar solution through the heat exchanger, but it's not mandatory.
* Hoses and Connectors: If you're using a submersible pump, you'll need hoses and connectors to create a closed-loop system for circulating the vinegar solution.


Steps to Clean the Heat Exchanger with Vinegar:
Turn Off the Unit: Ensure that the tankless water heater is turned off, and disconnect the power supply to the unit. Safety should always be a top priority when working on any appliance.
Isolate the Unit: Close the water inlet and outlet valves on the tankless water heater. This isolates the unit from the water supply and prevents the vinegar solution from flowing into your plumbing.
Create the Vinegar Solution:
Fill a bucket with a mixture of equal parts water and white distilled vinegar. The specific quantity will depend on the size of the heat exchanger and the severity of the scale buildup.
For moderate scale buildup, a 1:1 vinegar-to-water mixture is typically sufficient. For heavier scale, you can use a stronger vinegar solution.
Prepare the Circulation System (optional): If you have a submersible pump, set up a closed-loop system using hoses and connectors. One hose should be connected to the pump's outlet and submerged in the vinegar solution in the bucket, while the other hose should be connected to the pump's inlet and connected to the water inlet valve on the tankless water heater. This setup allows you to circulate the vinegar solution through the heat exchanger.
Start Circulation (if using a pump): If you're using a submersible pump, turn it on to circulate the vinegar solution through the heat exchanger. If not using a pump, proceed to the next step.
Let the Solution Sit: Whether you're using a pump or not, let the vinegar solution sit in the heat exchanger for at least 45 minutes to an hour. This allows the vinegar to dissolve and break down the scale deposits.
Rinse with Water: After the soaking period, thoroughly rinse the heat exchanger by connecting a garden hose to the water inlet valve on the tankless water heater. Make sure the water supply is turned on, and allow clean water to flow through the heat exchanger for several minutes. This helps flush out any remaining vinegar solution and loosened scale deposits.
Recommission the Unit: After rinsing, reopen the water inlet and outlet valves on the tankless water heater. Ensure that there are no leaks, and reconnect the power supply to the unit.
Test the Hot Water: Turn on hot water faucets in your home to ensure that the tankless water heater is operating correctly and delivering hot water at the desired temperature. This helps purge any remaining vinegar solution from the system.

By following these steps, you can effectively clean the heat exchanger on your Noritz NR66 OD tankless water heater using a vinegar solution. Regular descaling maintenance helps maintain the unit's efficiency and prolong its lifespan. If you're unsure about performing this task yourself or have any concerns, consider consulting a professional plumber or technician experienced in tankless water heater maintenance for guidance and assistance.