Can You Paint A Rinnai Heater?

Do you want to paint your Rinnai heater but wonder if doing so will damage the unit? We did comprehensive research to answer your question.

You can paint a Rinnai heater. But for your own safety, make sure that the wiring is not compromised. Also, you should pick a suitable paint that will adhere to the heater.

This post will provide instructions on how to paint a Rinnai heater. We'll discuss some risks you should be aware of and what you can do about them. Please keep reading!

Can You Paint A Rinnai Heater?

Close-up of person painter holding roller covered in blue paint.

You may want to paint your Rinnai heater to give it new life or to help it blend in with its surroundings. 

Painting the heater isn't a problem since its protective case prevents damage to the internal components. But you should not paint the small screen that displays the temperature.

There are a few factors you should consider before painting. We discuss them below.


Before painting your Rinnai heater, ensure it is in good condition and fully functional. Check the wires for faulty parts that need immediate repair. You'll want to repair the damaged wiring first or seek help from an HVAC technician to resolve wiring issues. 

Ensure that you cover the wires, as they may cause issues if they come into contact with the paint.

Type of Paint

It's important to know what paint you can use. These are some paints you can consider:


Enamel paint is oil-based, and it works well on hard surfaces. However, enamel paint may take longer to dry and settle.

Radiator Paint

Radiator paint is resistant to temperatures reaching up to 750 degrees Fahrenheit. You can use radiator paint for your water heater since it won't peel off even if the heater gets hot during normal use.

Do You Need Primer?

It's advisable to use a primer when painting the water heater. Primer helps enhance the adhesion and forms a protective layer that can prevent premature peeling.

See this primer on Amazon.

How Long Does A Rinnai Water Heater Warranty Last?

Homepage of Rinnai .Official website of company

A one-year warranty covers the Rinnai tankless water heater against system malfunction and defects. You can extend this warranty for up to five years when you register the product within 90 days of purchase.

You should read the full details of the warranty. In some instances, painting the water heater may void the warranty.

How Much Paint Do You Need?

Broken Modern Water Gas Heater Next to Shower Cabin Inside Elegant Clean Bathroom Interior., Can You Paint A Rinnai Heater?

One gallon of paint should be enough to cover a single unit. But the actual quantity can vary depending on the mode of paint application you opt for. You might use less paint if you spray paint the unit.

How to Paint A Rinnai Heater

If you're determined to paint the Rinnai heater, follow these steps:

  1. Turn off the unit and allow it to cool down for a few minutes.
  2. Use tape and plastic to protect the adjacent objects and walls from paint. Also, cover the labels on the heater. You want to avoid painting over any important information.
  3. Clean the Rinnai heater to remove dirt that may inhibit paint adherence.
  4. Use a scouring pad to make the surface rougher.
  5. Clean the unit again with water.
  6. Apply the primer and let it dry.
  7. Test the paint on a sheet of cardboard to check its quality.
  8. If the quality is good, go ahead and paint the Rinnai unit.
  9. Let the paint dry.
  10. Remove the tape and plastic coverings before turning on the unit.

Risks of Painting A Rinnai Heater

Water Heater on white bathroom wall

It's important to understand how paint might affect the unit. Here are some risks you may encounter.

Strong Odor

Paint can release a strong odor even after it gets dry. You'll want to check the paint quality to prevent this from happening.


Since the unit heats up, its external structure can also get hot. The hot temperature in the unit itself can make the paint peel off after a few weeks or months.

To minimize this risk, check the paint's quality and make sure it has the ability to adhere.

Expected Lifespan Of A Rinnai Heater

A Rinnai water heater can last up to 20 years, depending on product quality and usage. You'll want to keep the unit clean and allow it to cool down when not in use.

How To Maintain A Rinnai Heater

Maintaining your Rinnai heater will extend its lifespan. It will also keep you safe as you use the unit. Here are some maintenance tips to consider.

Temperature Settings

To prevent scalding and maintain comfort, you should not exceed 120 degrees Fahrenheit when setting the temperature on the Rinnai water heater. If you set the heater to a temperature that's too hot, it may damage the system in the long run.

Follow the steps below to adjust the temperature:

  1. To ensure your own safety, unplug the unit before proceeding.
  2. Remove the screws hidden behind the plastic tabs on the four corners of the plate and take off the front cover.
  3. Find the dip switches in the bottom right corner beneath the label.
  4. Locate and turn on the dip switch. Use a small screwdriver if needed.
  5. Reinstall the front cover and reclip the plastic tabs.
  6. Reconnect the unit.

Filter Cleaning

The filter protects the heater's internal components so that it performs optimally. You'll want to clean the filter to remove the dust, debris, and chemicals that accumulate over time. 


Flushing means draining the residual chemicals, such as scale or lime, caused by regular use of the unit. You can opt to do this yourself, but it might be best to relegate the task to a professional. 

Over time, mineral buildup in a tankless water heater can erode the walls of the heating chamber. To properly maintain and clean your water heater, it is critical to flush those mineral deposits at least once a year.

How Much Does A Rinnai Heater Cost?

Depending on the size, a new Rinnai heater can cost $1,000-2,000. You should choose the most affordable unit without compromising product quality. But you also want to strike a healthy balance between performance and cost. 

Be sure to buy your Rinnai heater from an authorized dealer and check the label of the product to avoid purchasing a counterfeit unit.

How To Paint A Rinnai Wall Heater

A Rinnai wall heater enables you to maintain comfortable temperatures in your home. 

See this Rinnai portable heater on Amazon.

Because the unit is portable, you should take it outside and paint to avoid dripping paint on the floor. Simply follow these steps:

  1. Turn off the unit and let it cool down for a few minutes.
  2. Switch the breaker off.
  3. Unplug the unit and take it outside. Depending on the installation, you might need to loosen the nuts on its bottom part to detach it from the floor.
  4. Prepare the area where you'll paint the unit. Make sure to put down old newspaper or plastic to avoid spilling paint on the ground.
  5. Cover the wirings and the filter to protect the internal system.
  6. Use a scuffing pad to make the surface a bit rough.
  7. Start painting.
  8. Let the unit dry before reinstalling it.

How To Paint A Rinnai Air Conditioner

Painting a Rinnai air conditioner can be more difficult than it seems. Because its external casing is usually smooth, the paint may fail to adhere.

To paint the air conditioner, follow these steps:

  1. Turn the unit off and cover the wires, air filters, and surrounding area.
  2. Prepare the paint and the primer. Canned paint is a good option for quick application.
  3. Wipe the external surface with a scuffing pad.
  4. Paint the air conditioner.
  5. Let the paint dry before turning on the unit.


Broken Modern Water Gas Heater Next to Shower Cabin Inside Elegant Clean Bathroom Interior

This article addressed the factors to consider when painting a Rinnai heater. We also discussed the different types of paint you can use and how to paint the unit correctly.

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