Noritz CB Boilers 
Review and Buying Tips

Explore the combination boilers from Noritz CB series, designed for efficient water and space heating in residential homes. Built as the indoor models only, CB series offers two models; CB199 and CB180 utilizing natural gas and propane. Both models are designed with the condensing and tankless technology, utilizing direct vent (DV) system.


Models review

Noritz CB boilerNoritz CB

Noritz CB boilers are combination residential boilers that utilize direct venting (DV) system and condensing technology, and are available as; Noritz CB199-DV that operates with the power ranging from 18,000 BTU to the maximum of 199,000 BTU (Turndown Ratio of 6.7) and water flow of 9.3 GPM, and smaller CB180-DV model that is able to produce up to 180,000 BTU (Turndown Ratio of 5.6) and water flow of 9.1 GPM.

High hot water delivery rate ensures effective whole house water and space heating using the radiator, baseboard, and radiant hydronic systems. Both models are recommended for homes with up to 4 baths.


Generating hot water for space heating

Noritz CB boilers are also designed for space heating allowing the maximum gas input of 120,000 BTU for the CB199 model, and 100,000 BTU for the CB180 models, reaching the temperatures from 100 F to 180 F. CB boilers are recirculation compatible so users can take advantage to get the hot water faster.

Efficient heating

Both combination boilers utilize three stainless heat exchangers; primary, secondary and DHW plate heat exchanger, and with the help of condensing technology can produce high 95% efficiency, making the units Energy Star compliant and great energy savers. They do not store water but use the tankless design to heat the passing water – on demand.

Also, with the built-in outdoor temperature reset control the temperature settings automatically adjust when the outside temperature change, therefore improving the efficiency and performance.

Users can adjust the temperature with a remote between 90 and 140 F for domestic water heating, and from 100 to 180 F for space heating.

Internal pump

The boilers are equipped with the internal circulation pump for use in the heating loop and to ensure sufficient water flow through the heat exchanger and plumbing system.

Control panel

The control panel located at the front of the unit allows easy control and monitoring of the heating parameters. The function buttons allow users to turn the unit ON, OFF or cancel the operation. Dial buttons allow users to set and change the DHW and heating temperature, and large display to show the temperature, time, heating mode, icon display, and error codes during failure.


As the CB water heaters are built for the indoor use only, the venting system for removing the exhaust gases out is a must. The units are factory made to utilize DV system with the PVC, PP and CPVC pipes, 2" or 3" in diameter and maximum 100 ft. in length, while with the appropriate kit these are capable of using the single vent (SV) as well. This is possible due to the lower temperature of flue gases of up to 149 F.

Compact size

With the maximum size of 17.3“ x 28.7” x 14.8” and weight of 90 lbs. you can easily put the boiler on the wall, therefore providing more floor space for other use.

Safety features

The Noritz CB series uses the following safety features:

  • Flame rod
  • Automatic overheat protection device
  • Gas leak detector sensor
  • Water leak detector sensor
  • Exhaust temperature sensor
  • Pressure sensor low water cutoff
  • Heating supply temperature sensor
  • Freeze protection (using the internal pump and burner)


Models/Specs Noritz CB199 Noritz CB180
Power (BTU) 18,000-199,900 18,000-180,000
Water flow (GPM) 0.5-9.3 0.5-9.1
max # of baths 4 4
Water/gas connections (inch) 3/4 3/4
Temperature (F) 90-140 (DHW)
100-180 (space)
90-140 (DHW)
100-180 (space)
Energy factor 0.95 0.95
Warranty 10/5 10/5


Noritz CB combination boilers come with the 10-year warranty on the heat exchangers. These models are recommended for homeowners who prefer having one high-efficient unit to supply hot water and provide space heating. Noritz CB is an excellent solution for those homeowners wanting to replace an old, tank-type water heater while taking advantage of the easy handling and installation and saving the floor space for other use.


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