The Benchmark™ hot water boilers can support natural gas with propane backup in environments with discounted “interruptible” gas rates or where dual fuel capability is mandated, the company says. To switch energy sources, users manually rotate a three-way ball valve located on the front of the unit. According to the manufacturer, no changes in controls, settings, or calibration are necessary. Designed for use in any closed-loop hydronic system, these boilers have an input of 2 million Btuh, an ASME working pressure of 150 psig, and a water volume of 27 gallons. Other features of the boilers include 15:1 turndown ratio, internal low-water cutoff (manual reset), temperature control ±2 degrees F, and either conventional or direct venting capabilities. According to the manufacturer, the efficiency of the boilers increases as the load decreases due to their unique inverse efficiency curve.

AERCO International, 159 Paris Ave., Northvale, NJ 07647; 800-526-0288 or 201-768-2400; 201-768-7789 (fax);

eProduct #188