Reznor 105,000 BTU Natural Gas Unit Heater - Quiet Forced Air

In this review of the Reznor UDXC-100, the bottom line is simple: it is a heavy-duty indoor natural gas heater built for garages, workshops, and light industrial spaces that need dependable, quiet heat. The reviewer found the unit's dual firing levels and an 83% thermal efficiency to be the single biggest reason to consider it if you want energy-conscious performance without noisy operation. Installation requires appropriate mounting hardware and following local codes, but the included horizontal Cat 3 Z-vent kit and robust construction make the UDXC-100 a practical long-term heating solution.

Key Features

• Adjustable Heat Output: Two firing levels let the heater run at a lower 61,005 BTU for mild days or up to 87,150 BTU for colder conditions, so it adapts to changing needs.
• Efficient Operation: The unit achieves around an 83% thermal efficiency rating, helping reduce wasted fuel compared with older, less efficient models.
• Quiet Forced Air: A low static axial propeller fan and vibration isolation make the heater noticeably quieter than many commercial shop heaters during operation.
• Durable Heat Exchanger: The TCORE2 titanium-stabilized aluminized steel heat exchanger and patented single-burner combustion are built for lasting service life.
• Service Access and Controls: A removable front face, hinged access door panel, integrated circuit board display, and status LED simplify setup and troubleshooting.
• Included Venting Kit: The listing includes a horizontal category 3 single wall Z-vent kit for sidewall venting, which helps streamline initial installation.

Who It's For

This heater is well suited to homeowners with large attached or detached garages, small shop owners, and light industrial spaces where a ceiling-mounted or suspended indoor heater is preferred. People who value quieter operation and efficiency will find the UDXC-100 appealing because of its low static fan and 83% efficiency.

It is not aimed at consumers who need portable or space-limited electric heaters, or those who cannot accommodate hard-venting out a sidewall. Buyers who need ceiling mount brackets should note that mounting hardware is sold separately and professional installation may be required to maintain warranty coverage.

Pros & Cons

Pros

• Dual firing levels provide flexibility for different weather and usage patterns.
• Quiet, vibration-isolated propeller fan reduces noise in enclosed work areas.
• Robust construction with a TCORE2 heat exchanger and integrated controls simplifies maintenance.
• Includes a horizontal Cat 3 Z-vent kit to expedite sidewall venting.

Cons

• Mounting brackets are not included so additional parts and installation planning are needed.
• Requires compliance with local codes and professional installation to ensure the warranty remains valid.

Specifications

Model	UDXC-100 (105,000 BTU)
Fuel Type	Natural Gas
Heat Output	Low fire 61,005 BTU / High fire 87,150 BTU
Thermal Efficiency	Approximately 83%
Fan	Low static axial propeller fan, vibration isolated
Venting	Horizontal Cat 3 single wall Z-vent kit included
Warranty	9 year heat exchanger; 4 year electrical and mechanical

Our Verdict

The Reznor UDXC-100 is a practical choice for garages, workshops, and small commercial spaces that need steady indoor natural gas heat with quieter operation and good efficiency. It offers durable construction and convenient controls, and the included venting kit reduces installation complexity, making it a solid long-term investment for anyone prepared to arrange proper mounting and code-compliant installation.

Frequently Asked Questions

Is the venting kit included?
The listing includes a horizontal category 3 single wall Z-vent kit for sidewall venting.

Can this be ceiling mounted?
Yes, the heater has four suspension points with threaded-nut retainers for ceiling hanging, but mounting hardware is sold separately.

What warranty coverage is provided?
Heat exchanger, burner, and flue collection box assembly have a 9 year warranty; electrical and mechanical components have a 4 year warranty, with proper installation required for validity.