Flagro USA Dual Fuel Construction Heater — 400,000 BTU, Natural Gas or Propane, Model# F-400T
Reliable Heat. Dual Fuel Flexibility. Built for Demanding Jobs.
The Flagro USA Dual Fuel Construction Heater (Model# F-400T) delivers up to 400,000 BTU of powerful, consistent heat for commercial and industrial applications. Designed for versatility and ease of use, this unit operates on either propane or natural gas—simply turn the fuel selector valve to switch between fuel sources in seconds.
Built to withstand tough jobsite conditions, the F-400T features a 100% flame safeguard system, forced-air heating, and a durable construction that ensures long-lasting performance. With a 2,000 CFM blower and heating capacity of up to 5,000 square feet, it provides efficient, even heat distribution wherever you need it most.
The Flagro F-400T is engineered for safety, efficiency, and low maintenance, making it the ideal choice for construction sites, workshops, warehouses, and other large open spaces requiring dependable heat in cold conditions.
Features & Benefits
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Dual Fuel Operation: Runs on either propane or natural gas for maximum flexibility.
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Powerful Heat Output: Delivers up to 400,000 BTU/hour to heat spaces up to 5,000 sq. ft.
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100% Flame Safeguard System: Ensures safe and reliable performance.
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Forced-Air Design: 2,000 CFM blower provides efficient, even heat distribution.
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Automatic Shutoff: Adds an extra layer of safety for peace of mind.
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Durable Construction: Built to handle commercial and industrial environments.
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Environmentally Friendly: Produces minimal combustion impurities.
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Low Maintenance: Simple to operate with minimal servicing required.
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Thermostat Included: Offers precise temperature control.
Specifications
| Attribute | Specification | 
| Item # | 23813 | 
| Brand | Flagro Inc | 
| Manufacturer’s Warranty | 12 months parts / 12 months labor | 
| Ship Weight | 160 lb | 
| Max. Heat Output | 400,000 BTU/hour | 
| Heat Type | Forced Air | 
| Heating Capacity | 5,000 ft² | 
| Indoor/Outdoor Use | Indoor and Outdoor | 
| Thermostat Included | Yes | 
| Blower Included | Yes | 
| Blower CFM | 2,000 CFM | 
| Remote Included | No | 
| Oxygen Depletion Sensor | No | 
| Fuel Consumption | 4.4 GPH | 
| Automatic Shutoff | Yes | 
| Electrical Requirement | 115V | 
| Barrel Diameter | 15.5 in. | 
What’s Included
- (1) Flagro USA Dual Fuel Construction Heater
- Product Manual
Manufacturer’s Warranty
- 12 Months Parts / 12 Months Labor
Frequently Asked Questions (FAQ)
Q1: Do I need to vent the exhaust outside when using propane?
A: Yes. Always provide adequate ventilation. For every 1,000 BTU of heat, one square inch of fresh air must be supplied. The flow of combustion and ventilation air must not be obstructed.
Q2: Can ducting be attached to this heater to distribute heat?
A: No. Ducting should not be added, as the heat output is too high and could melt duct materials.
Q3: Does this heater have an automatic shutoff feature?
A: Yes, the F-400T includes an automatic shutoff for enhanced safety.
Q4: What is the electrical requirement for this heater?
A: The unit operates on 115V electricity.
Q5: What gas pressure is required for operation?
A:
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Propane: 11" water column (approx. 0.397 psi)
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Natural Gas: 3.5" water column (approx. 0.126 psi)
 If your gas supply pressure is higher, an external regulator is required.
Q6: What is the fuel consumption rate?
A:
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Propane: Approximately 18.5 lbs/hour
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Natural Gas: Approximately 380 cubic feet/hour
Q7: What is the diameter of the heater’s barrel?
A: The barrel measures 15.5 inches in diameter.