How to Convert a Natural Gas Reznor Heater into a Propane Heater

Converting a natural gas Reznor heater into a propane-fired heater is a straightforward process, but it requires careful attention to detail and adherence to the manufacturer’s instructions. This comprehensive guide will walk you through the step-by-step process, ensuring your Reznor heater operates safely and efficiently on propane.

Obtaining the Correct Gas Conversion Kit

The first step in the conversion process is to obtain the appropriate gas conversion kit for your Reznor heater model. Reznor offers a wide range of conversion kits designed specifically for their various heater models and sizes. It’s crucial to select the correct kit that matches your Reznor heater’s specifications, as using the wrong kit can lead to improper operation and potentially dangerous situations.

When selecting the conversion kit, you’ll need to know the model number and size (BTU/h) of your Reznor heater. This information can typically be found on the manufacturer’s rating plate located on the heater. Once you have this information, you can consult the Reznor gas conversion kit selection guide or contact the manufacturer directly to ensure you purchase the correct kit for your specific model.

Removing the Factory-Installed Orifice

how to convert my natural gas reznor heater into propane

With the conversion kit in hand, the next step is to remove the factory-installed orifice from your Reznor heater. This orifice is designed for natural gas operation and must be replaced with the propane-specific orifice included in the conversion kit.

To remove the factory orifice, you’ll need to access the burner assembly, which may require removing the heater’s front panel or other components. Consult the manufacturer’s instructions for the specific steps to access the burner assembly on your Reznor heater model.

Once you’ve gained access to the burner assembly, locate the factory-installed orifice and carefully remove it using the appropriate tools, such as a wrench or socket. Take note of the orifice size, as you’ll need to compare it to the new orifice included in the conversion kit.

Installing the Burner Orifice from the Conversion Kit

With the factory orifice removed, it’s time to install the new burner orifice from the Reznor gas conversion kit. The conversion kit will include a specific orifice size that is designed to work with propane gas.

Carefully insert the new orifice into the burner assembly, ensuring it is properly seated and tightened. Again, refer to the manufacturer’s instructions for the specific steps and torque specifications required for your Reznor heater model.

Adjusting the Manifold Pressure

In addition to the orifice change, you may need to adjust the manifold pressure of your Reznor heater to ensure proper operation on propane gas. The required manifold pressure can vary depending on the elevation of your location.

Reznor provides a table in their conversion kit instructions that outlines the appropriate manifold pressure settings for natural gas and propane gas at different elevation ranges. Consult this table and adjust the manifold pressure accordingly, using a manometer or other pressure measurement device.

It’s important to note that the manifold pressure adjustment should be performed by a qualified service technician, as improper adjustments can lead to unsafe operation or damage to the heater.

Installing New Ratings Plates

Depending on the specific Reznor heater model and conversion kit, you may also need to install new ratings plates that reflect the heater’s conversion to propane operation. These plates provide important information about the heater’s specifications and are required by local codes and regulations.

The conversion kit will typically include the necessary ratings plates, and the instructions will guide you on where to install them on the heater. Ensure that the new plates are securely affixed and that all the information is accurate and legible.

Completing the Conversion Process

Once you’ve completed the steps outlined above, the final step is to have a qualified service person perform a comprehensive inspection and testing of the converted Reznor heater. This is a crucial step to ensure the heater is operating safely and efficiently on propane gas.

The service technician will perform a series of checks, including:

  • Verifying the correct orifice size and manifold pressure settings
  • Checking for gas leaks
  • Performing a combustion analysis to ensure proper air-fuel mixture
  • Ensuring the heater’s safety controls are functioning correctly
  • Updating the heater’s documentation to reflect the conversion to propane

Only after the service technician has completed these checks and signed off on the conversion should you consider the process complete and the heater ready for safe operation on propane gas.

Remember, the conversion process involves working with gas lines and appliances, which can be dangerous if not done correctly. Always prioritize safety and consult with a qualified professional if you have any doubts or concerns about the conversion process.


Converting a natural gas Reznor heater into a propane-fired heater is a straightforward process, but it requires attention to detail and adherence to the manufacturer’s instructions. By following the steps outlined in this guide, you can successfully convert your Reznor heater to operate on propane gas, ensuring safe and efficient heating for your home or commercial space.

Remember to always consult the manufacturer’s instructions, obtain the correct conversion kit, and have the conversion performed by a qualified service technician. With the right approach, you can enjoy the benefits of propane-powered heating while maintaining the reliability and performance of your Reznor heater.


  1. Reznor Gas Conversion Kit Instructions – Reznor
  2. Gas Conversion Kits and Instructions – Reznor
  3. Reznor Gas Conversion Kits – eComfort