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KS399 375,000 BTU Output Keystone Condensing Boiler
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MANUALS (2)
Replacement Parts
Product Highlights
Description
The Triangle Tube brand has been discontinued by the manufacturer as of 11/3/2025. Suggested replacement units will be available on our website and replacement parts will continue to be available as supplies last. If you'd like any further assistance, please contact our customer service team.
Note: Product Title reflects this boiler's IBR Net Output Rating
Triangle Tube's Keystone Series Condensing Boilers are designed for large residential and light commercial applications. The stainless steel heat exchanger and burner provides high efficiency, low emissions, and a high turndown to minimize short cycling. With maximum inputs of 850 MBH for boilers and 500 MBH for water heaters, the Keystone series can meet most needs with a single unit. For larger requirements the advanced control allows units to be joined and function with parallel modulation for maximum efficiency.
Features:
Specs
| Fuel Type: | Propane Natural Gas |
|---|---|
| Efficiency: | 94% |
| System Type: | Hydronic (Water) |
| Vent Type: | Direct Vent |
| Gas Connection: | 3/4" |
| Features: | EI/Spark Ignition Condensing |
| Water Connection: | 1-1/4" |
| Air Intake: | 4" |
| Vent Diameter: | 4" |
| BTU Input: | 399000 |
| IBR Rating: | 375000 |
| Combustion Efficiency: | 95.6 |
| Depth (Inches): | 31" |
| Width (Inches): | 24-1/2" |
| Height (Inches): | 38" |
Questions?
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KS 399
Replacement Parts
SKU:Â KS399
Brand:Â Triangle Tube
