Reznor 105,000 BTU Natural Gas Garage Heater UDXC-100 - Ceiling Mount

Our review of the Reznor UDXC-100 105,000 BTU natural gas unit heater finds it best suited to garages, workshops, and small commercial bays where steady, powerful heat and quiet operation are priorities. The bottom line: this model delivers strong forced-air heating with an efficient TCORE2 heat exchanger and two practical firing levels, making it a solid choice when you need reliable indoor gas heat that can be ceiling mounted or bracketed for wall install.

Key Features

• High output: The UDXC-100 offers a rated capacity of 105,000 BTU with two firing levels so it can provide higher output for very cold days and a lower setting for milder conditions.
• Solid efficiency: With an approximate 83% thermal efficiency rating, the heater converts a large share of gas input into usable heat for indoor spaces.
• Durable heat exchanger: A TCORE2 titanium-stabilized aluminized steel heat exchanger and patented single-burner combustion are built for long service life in demanding environments.
• Quiet forced air: The low static pressure axial propeller fan operates with reduced vibration and noise, which keeps shop noise down while moving warm air effectively.
• Serviceable design: The updated cabinet with removable front face and hinged access door simplifies routine servicing and component access.
• Mount flexibility: Threaded-nut retainers at four suspension points allow ceiling hang or bracketed wall mounting when appropriate hardware is used.

Who It's For

The UDXC-100 is aimed at homeowners and small business operators who need a robust indoor gas heater for a garage, workshop, small warehouse, or service bay. Installers and facilities managers will appreciate the performance range, integrated controls, and service access when planning long-term upkeep.

Those who should look elsewhere include users who require ventless or outdoor-only heaters or projects that must avoid any fuel-burning appliance indoors; this unit requires proper venting (category 1 or category 3 depending on routing) and code-compliant installation to validate the warranty.

Pros & Cons

Pros

• High and low fire settings give flexible heat output for varying winter conditions.
• Quiet axial propeller fan and power venting produce effective forced-air distribution without excessive noise.
• Durable construction with a titanium-stabilized heat exchanger and integrated electronics reduces long-term maintenance concerns.
• Removable front and hinged access door make routine service tasks faster.

Cons

• Mounting hardware and vent piping are sold separately, so additional parts and planning are required for a complete installation.
• As a gas-fired indoor unit, it requires proper venting and professional installation to meet local codes.

Specifications

Model	UDXC-100 (105,000 BTU)
Fuel Type	Natural Gas
Rated Output	105,000 BTU (two firing levels)
Thermal Efficiency	Approximately 83%
Fan Type	Low static pressure axial propeller fan
Heat Exchanger	TCORE2 titanium-stabilized aluminized steel
Warranty	9 year heat exchanger; 4 year electrical and mechanical

Our Verdict

The Reznor UDXC-100 is a practical, value-oriented indoor gas unit heater for garages and small commercial spaces that need dependable forced-air warmth and quiet operation. Given its robust heat exchanger, dual firing levels, and serviceable cabinet design, it represents good long-term value for installations that can provide proper venting and mounting hardware.

Frequently Asked Questions

Can this heater be ceiling mounted?
Yes, the unit has threaded-nut retainers at four suspension points for ceiling hanging; mounting brackets are sold separately.

What venting is required?
Vertical roof venting uses category 1 double wall B-vent; horizontal sidewall venting requires category 3 single wall vent pipe per installation instructions.

Is the fan noisy?
No, the low static pressure axial propeller fan is designed for quiet operation with vibration isolation for indoor environments.