• High efficiency condensing boiler
• Electronic PID modulating control with large color touchscreen display
• Displays holds, alerts, and errors in clear text
• Complete diagnostics for analog and digital inputs
• Accepts external analog modulation signal
• Built-in cascade function for up to four Keystone boilers
• Multiple circulator control of boiler, system, and domestic circulators, with delay
• Outdoor reset with customizable reset curves, domestic hot water priority and warm weather shutdown
• Modulation down to 10% of full fire (10:1 turndown)
• Sealed combustion chamber
• Pre-mix stainless steel burner
• Low NOx - 2012 SCAQMD certified
• Horizontal or vertical direct vent
• Vent and combustion air pipe lengths of up to 100’
• Built-in condensate trap
• Vent temperature cutoff feature
• Direct spark ignition system
• 160 psi maximum working pressure
• Stainless steel heat exchanger with welded construction (no gaskets)
• ASME “H” stamp
• 75 psi (517 kPa) ASME Rated pressure relief valve
• Water flow switch
• Temperature & pressure gauge
• Alarm output
• Outdoor temperature sensor
• On/off service switch
• Manual reset temperature high limit
• Burner site glass

Keystone Condensing Boilers provide powerful solutions for large residential and light commercial applications with 5 models with inputs from 399 to 850 MBH. These products feature a stainless steel heat exchanger with a thermal efficiency between 95 and 97%. Their compact design minimizes floor space while the cabinet provides easy access to all components. The large user friendly control interface makes set-up easy. The advanced control modulates the boiler with a 5 to 1 turndown ratio. Up to 8 boilers can be joined in a cascade while the control features parallel modulation and boiler rotation to maximize efficiency and service life

Triangle Tube Boiler Installation & Warranty Information

We recommend that the installation of all Triangle Tube Boilers and Water heaters be done by a licensed, trained and qualified technician with the proper knowledge and background.

Should you experience an issue during the installation or the initial startup of the unit, please do not contact the manufacturer. You should have the technician that installed the unit contact either us or the manufacturer. Triangle Tube cannot accept any service or warranty calls from anybody but a licensed technician.

Neither we or Triangle Tube can be held liable for improper installation and operation of any Triangle Tube boiler product purchased from our company. Should a warranty issue arise where parts will need to be replaced, an installation receipt will be required along with your sales receipt. Failure to provide a receipt or invoice may result in the warranty not being honored.