Can I convert the Noritz NCC300 DV from natural gas to propane, and what are the necessary steps?

Converting a Noritz NCC300 DV tankless water heater from natural gas to propane (also known as LP gas) involves several steps and considerations. This process should only be performed by a qualified technician or plumber who is familiar with the specific conversion requirements for your unit. Converting a gas appliance incorrectly can result in safety hazards and damage to the unit. Here are the necessary steps for converting the Noritz NCC300 DV from natural gas to propane:

1. Obtain the Propane Conversion Kit:
Contact Noritz or an authorized Noritz dealer to obtain a propane conversion kit designed for your specific model, the NCC300 DV. This kit should include all the necessary components for the conversion, such as propane orifices, gas valves, and instructions.
2. Turn Off the Gas Supply:
Before beginning any work on the water heater, shut off the gas supply to the unit. This is typically done at the gas shut-off valve located near the water heater or at the main gas supply line.
3. Disconnect the Gas Supply Line:
Carefully disconnect the natural gas supply line from the water heater. Use an adjustable wrench to loosen and remove the gas line connection. Be prepared for residual gas to escape when disconnecting.
4. Remove the Burner Assembly:
To access the burner and orifices, remove the burner assembly from the water heater. This typically involves disconnecting the burner gas line and removing any securing brackets.
5. Replace the Orifices:
Install the propane orifices provided in the conversion kit. These orifices are designed for propane gas and are smaller than the natural gas orifices to accommodate the different gas pressure and flow requirements of propane.
6. Adjust the Gas Valve:
Adjust the gas valve on the water heater to the propane setting. This adjustment may involve changing the gas pressure setting and configuring the valve for propane use. Refer to the instructions provided in the conversion kit for specific details on adjusting the gas valve.
7. Inspect and Test:
After completing the conversion, carefully inspect all connections for leaks. Use a gas leak detector solution or soapy water to check for any bubbles at the connections. Address any leaks immediately.
Reassemble the burner assembly and make sure all components are properly secured.
Turn on the propane gas supply and check for proper ignition and combustion. Ensure that the water heater operates safely and efficiently.
8. Adjust Air-Fuel Mixture (if necessary):
Depending on the specific conversion kit and unit, you may need to adjust the air-fuel mixture to achieve optimal combustion. Follow the instructions provided in the kit to make any necessary adjustments.
9. Update Labels and Documentation:
After completing the conversion, update any labels or documentation on the water heater to indicate that it has been converted to propane. This is important for future reference and for any service technicians who may work on the unit.
10. Follow Local Codes and Regulations:
Ensure that the conversion complies with local building codes, regulations, and safety standards for propane installations. Local codes may require specific venting configurations or safety measures for propane appliances.
11. Perform a Function Test:
Finally, perform a thorough function test of the water heater to ensure it operates correctly and safely in its new propane configuration. Verify that it provides hot water at the desired temperature.


It's important to emphasize that converting a gas appliance should only be done by a qualified technician or plumber who is certified to work with propane gas and is experienced with Noritz tankless water heaters. They will have the knowledge and tools necessary to perform the conversion correctly and safely.

Attempting to convert the Noritz NCC300 DV or any gas appliance without the appropriate expertise can result in gas leaks, unsafe operation, and damage to the unit. Additionally, performing an improper conversion may void any warranties or certifications associated with the water heater. Always prioritize safety and consult with a professional when making such modifications.