250,000 Btu Tf Series Unit Heater With 5" Vent

250,000 Btu Tf Series Unit Heater With 5" Vent

Brand: Sterling

SKU: TF250

Regular price: $1,741.99

Availability: In stock.


The Sterling Model TF gas-fired unit heater offers a highly efficient, extremely durable alternative to the traditional clam shell design. These propeller type units combine the latest tubular heat exchanger and inshot burner technology with the quality and reliability you have come to know from Sterling. Units are available in sizes 100 to 400 MBH. Standard energy saving features like the direct spark ignition and power venting reduce standby losses and offer improved seasonal effi ciencies. The Model TF unit is certified by ETL as providing 83% thermal (combustion) efficiency. 

Tubular Heat Exchanger

The Sterling tubular heat exchanger has been designed to provide maximum and uniform heat transfer. The low pressure drop associated with this design enables heated air to be evenly distributed to the conditioned space. This curved, non-welded serpentine design experiences less thermally induced stress making it highly durable for signifi cantly longer service life. All Sterling tubular heat exchangers are constructed of heavy duty 20-gauge aluminized steel. Optional 409 stainless steel heat exchangers are also available.

Direct Spark Ignition System

Sterling Model TF units utilize a direct spark pilotless ignition of the burner, providing fast heat delivery. This highly reliable and effi cient ignition system incorporates an integrated electronic control board to regulate the system sequence of operation, including an onboard LED indicator for simple troubleshooting. 


The Sterling Model TF unit heater is ETL certifi ed in accordance with categories I and III venting requirements. This certifi cation allows units to be vented both vertically and horizontally using either single wall or double wall venting materials. This venting fl exibility of the Model TF unit heater makes installation easier and more cost effective by allowing the installer to utilize existing venting components. 

Control Accessibility

Designed with the service person in mind, every component of the Sterling Model TF is easily accessible. Ignition and fan controls are located in one centrally located control panel. The access door provides control isolation as well as a pleasing exterior appearance.


  • 20 gauge tubular heat exchangers
  • 9 sizes ranging from 100 to 400 MBH
  • Inshot type burner
  • Hot surface pilot ignition system
  • 20 gauge jacket panels w/ baked enamel finish
  • Power vented
  • Easy access control panel
  • Certified for category I and III venting
  • Terminal strip low voltage wiring
  • 81% thermal efficiency
  • 10 year warranty
  • Factory fire tested