Reznor UDX 300,000 BTU Natural Gas Unit Heater - NUDX300

Reznor UDX 300,000 BTU Natural Gas Unit Heater - NUDX300

Reznor model UDX gas-fired unit heaters are great for space heating applications. These units are power vented to eliminate heat losses up the flue pipe. Each heater features a two-tone black and white powder coated, scratch-resistant paint scheme and has clean rounded corners and edges with no visible screws or fasteners. For air circulation, the UDX series utilize an axial propellor fan.

Features

• 83% AFUE Efficiency
• TCORE2 titanium stabilized aluminized steel heat exchanger
• Multi-try, direct spark ignition with time lockout
• Vibration/noise isolated fan and venter motors designed for low noise operation
• External status indicating LED that blinks if there is a problem that needs service
• 7-segment display board that shows fault code for quick and easy troubleshooting
• Optional integrated downturn nozzle and integrated vertical louvers

What our Experts Think

• Built for serious heating demands
  With 300,000 BTU input, this unit is engineered for large commercial, industrial, or warehouse spaces, delivering powerful and consistent heat output where smaller units fall short.
• Strong efficiency for its class
  Operating at around 83% AFUE, it strikes a solid balance between fuel efficiency and high-capacity performance, making it a practical choice for long operational hours.
• Durability you can rely on
  The TCORE2® aluminized steel heat exchanger is designed for longevity under demanding conditions—ideal for environments with heavy-duty usage.
• Smart diagnostics & easy servicing
  Features like a 7-segment display board and LED diagnostics simplify troubleshooting, reducing downtime and maintenance costs.
• Quiet, low-vibration operation
  Despite its size, the unit uses vibration-isolated motors and an axial fan to maintain relatively low noise levels—important for workspaces.
• Efficient heat distribution
  With airflow reaching ~3,800+ CFM and up to 90+ ft air throw, it ensures wide and even heat coverage across large areas.

Q&A

Q1: What size space can the Reznor UDX300 heat?
A: With 300,000 BTU input and ~249,000 BTU output, it’s ideal for large commercial, industrial, or warehouse spaces requiring powerful, consistent heating.

Q2: How efficient is the Reznor UDX300 heater?
A: It offers up to 83% AFUE efficiency, delivering strong heat output while minimizing energy waste.

Q3: What type of fuel does this unit heater use?
A: The NUDX300 operates on natural gas and can be converted to propane with an optional kit.

Q4: Is the Reznor UDX300 suitable for commercial use?
A: Yes, it’s designed for commercial and industrial applications, including workshops, garages, and large facilities.

Q5: What makes the UDX300 durable and reliable?
A: It features a TCORE2 titanium-stabilized aluminized steel heat exchanger, ensuring long-lasting performance and resistance to corrosion.

Q6: Does it operate quietly?
A: Yes, the unit includes a low-noise axial fan with vibration isolation, making it quieter than many comparable heaters.

Q7: Is installation and maintenance easy?
A: The heater includes external gas connections, diagnostic LED indicators, and a simple control board, making installation and troubleshooting straightforward.

Q8: What are the key airflow and performance specs?
A: It delivers up to 3843 CFM airflow with an air throw of ~94 feet, ensuring even heat distribution across large areas.

Maintenance Tips

• Clean air pathways regularly: Keep fan blades, louvers, and intake areas dust-free to maintain proper airflow and efficiency (≈83% AFUE).
• Inspect heat exchanger annually: Check for cracks or corrosion to ensure safe combustion and long lifespan of the TCORE2® exchanger.
• Check gas pressure & ignition system: Verify proper operation of the direct spark ignition and gas connections to prevent misfires or inefficiency.
• Monitor venting system: Ensure the power vent and flue are clear of obstructions to avoid heat loss and unsafe exhaust buildup.
• Tighten electrical connections: Periodically inspect wiring, control board, and LED diagnostics for faults or loose connections.
• Lubricate and inspect motors: Keep fan and venter motors running smoothly to reduce noise and wear.
• Schedule professional servicing: Annual HVAC servicing helps maintain warranty compliance and peak performance.