• Sterling GG120 Gas Heater - 4070665
  • Sterling GG120 Gas Heater - 4070665
  • Sterling GG120 Gas Heater - 4070665
  • Sterling GG120 Gas Heater - 4070665
  • Sterling GG120 Gas Heater - 4070665
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This item ships by FREIGHT TRUCK
Free shipping is not available to AK and HI.
Retail: $1,219.00
Price: $1,029.00
Availability: In Stock - Usually ships in 1 to 2 days.
What are these options for?

Sterling GG gas heaters are an excellent option for heating garages, greenhouses, sheds, etc. Each Sterling GG heater includes: tubular heat exchanger, electronic ignition, power exhaust system, advanced diagnostic system for dependable worry-free operation, lots of safety features, high power fan to provide even heat distribution, rust-resistant aluminized steel exchanger, and a baked-on enamel finish made to protect them from harsh environments. Designed for propane or natural gas. Some wiring required. Requires 110/120v electricity.


  • 82% efficient
  • Made in the USA
  • Certified for residential, commercial, and industrial use
  • Direct spark ignition
  • Power vented exhaust
  • Separated combustion capable (concentric vent kit required)
  • Stainless steel burner is standard
  • Convenient diagnostic light and thermostat connections on outside casing
  • Mounting brackets and conversion kit included
  • 10 year warranty on the burner and heat exchanger

Heater Venting Options

Sterling GG heaters have the unique ability to be vented with a single exhaust pipe or with both an intake and exhaust pipe (referred to as separated combustion) by adding the concentric vent kit and piping. Click here to learn more about the benefits of separated combustion.

Heater Upgrade Options

Extended Parts Warranty
This extends the included 1 year parts warranty to 3 years. If replacement parts are needed, they will be provided no charge and shipped for free during the life of the warranty. Click here for terms

Heater Gas Type Setup
The heater will come equipped from the factory for whichever gas type you choose.
NOTE: A free conversion kit is also included in case you need to change the gas type in the future.

Stainless Steel Heat Exchanger
If the heater will be in a corrosive environment, upgrading to a stainless steel heat exchanger will increase the life of the heater. Units with stainless steel heat exchangers ship direct from Sterling. The average ship time is 2 to 3 weeks. Must be ordered with heater.

2 Stage Gas Valve
Heaters with a two-stage gas valve start on the 1st stage at half output and only switch to the 2nd stage, full output, if the temperature inside the room continues to drop. This allows the heater to run more efficiently saving gas and money. Units with 2 stage valves ship direct from Sterling. The average ship time is 2 to 3 weeks. Must be ordered with heater.

If the heater will be installed at a location that is over 5000' above sea level, Sterling makes a special high altitude model for this application. Units setup for high altitude (above 5000') ship direct from Sterling. The average ship time is 2 to 3 weeks. Must be ordered with heater.

Performance Specifications

For Greenhouse Sizing, use our Greenhouse Heater Size Calculator
Model Application BTU Input BTU Output W x D x H Weight (lbs)
GG30 1 to 1-1/2 Car Garage
200 to 400 Sq. Ft.
30,000 24,900 30" x 25 7/8" x 12 3/8" 60
GG45 2 to 2-1/2 Car Garage
400 to 600 Sq. Ft.
45,000 37,350 30" x 25 7/8" x 12 3/8" 65
GG60 3 to 3-1/2 Car Garage
600 to 800 Sq. Ft.
60,000 49,800 30" x 26 3/16" x 15 7/8" 80
GG75 4+ Car Garage
800 to 1000 Sq. Ft.
75,000 61,500 30" x 26 3/16" x 15 7/8" 85
GG90 Large Garage or Shop
1000 to 1200 Sq. Ft.
90,000 73,800 30" x 26 3/8" x 22 5/8" 95
GG105 Large Garage or Shop
1200 to 1400 Sq. Ft.
105,000 86,100 30" x 26 3/8" x 22 5/8" 105
GG120 Large Garage or Shop
1400 to 1600 Sq. Ft.
120,000 98,400 30" x 26 3/8" x 22 5/8" 110

Product Manuals, Tips, Specs, & Guides

Sterling GG Heater Specs and Dimensions

Sterling GG Heater Installation Manual

Model # GG120A1NSA11, GG120A1PSA11, GG120A2NSA11, GG120A2PSA11, GG120A1NSB11, GG120A1PSB11, GG120A2NSB11, GG120A2PSB11

Overall Customer Rating of 2 Reviews:

GG120 overhead propane heater

Heater was easy to hang, make electrical and gas connections. Once put into service, it worked with no issues at all. No adjustments or alterations were needed. It heats my 40’x60’ shop to a comfortable working temperature while outside it was snowing and wind blowing. I also like the fact that it is very quiet and I can have my radio playing without turning up the volume.


Awesome Heater

I have about 1200 sqft garage, not insulated and live in the north east. When it's below 0 outside this guy heats my garage no problem. I'll suffer on my gas bill but I was toasty building cars. I'm very happy! Easy to install and well built.