The CB Series of combination boilers (combi) from Noritz America Corp. feature high-efficiency condensing technology to deliver hot water for both residential plumbing and hydronic applications.
“Because the units are tankless, they are not continuously heating a large quantity of water,” says Patrick McQuillan, lead branch engineer at Noritz. “The burner only turns on when there is demand for heat or DHW (domestic hot water). If there is no water demand, no gas is being burned. Additionally, the CB prioritizes between heating and DHW. It never does both simultaneously. The logic of the programming is designed so you do not experience a drop in performance on either heating or DHW.”
The CB combi delivers up to 9.2 gpm of hot water and performs at 95 percent AFUE (annual fuel utilization efficiency), converting 95 percent of the Btuh input into usable heat. On the heating side, the combi accommodates multiple applications including radiators, baseboards, low- and high-mass radiant heating and air handlers. It weighs 90 pounds and is 17.3 inches wide, 28.7 inches tall and 14.8 inches deep.
“It’s a light unit that can be carried by one person,” McQuillan says. “It hangs on the wall, so it takes up little to no floor space. You also only need to run gas and vent lines for one unit — that means less cost for piping materials and fewer penetrations through the wall or roof.”
Available in two models, the CB180DV has a maximum gas input Btuh of 180,000 for hot water and 100,000 Btuh for space heating. The CB199DV has a maximum gas input Btuh of 199,000 for hot water and 120,000 Btuh for space heating. Little maintenance is required.
“Typically, with tankless water heaters, the biggest maintenance issue is flushing out the unit with vinegar or an acidic solution to clean out scale buildup due to hard water,” McQuillan says. “This is a concern for DHW tankless units, but not for boilers. The CB combi uses heat exchangers made of high-grade austenite stainless steel. Scale does not stick to stainless steel the same way it sticks to copper, so maintenance is less of an issue. However, Noritz still recommends that a flush be done on the DHW side of the loop.”
Other key features of the Noritz CB include a large internal heat loop circulation pump (maximum flow rate of 5 gpm at zero head), outdoor reset and temperature sensor, safety controls that prevent water from reaching scalding temperatures, premix combustion with negative pressure gas valve for consistent combustion and low, consistent levels of carbon monoxide and nitrogen oxide emissions. 714/433-2905; www.noritz.com.
