Free residential service call with any repair during normal business hours

CSI Mechanical

   (704) 600-6267

Serving Shelby, NC Metro Since 2010



  • Technical Specifications



    95 lbs

    Gas Consumption

    Min 18,000 btuh
    Max 180,000 btuh

    (NG & LP)

    Natural Gas/Propane

    Capacity Range

    0.4 GPM up to 9.8GPM

    Temperature Settings

    Domestic Mode: 90°F to 140°F – Heating Mode: 100°F to 180°F



  • Models and Accessories

    Model Number and Description

    Heating Mode Input- Gas Consumption

    Standard input : 18,000 BTUh to 180,000 BTUh Heating mode input : 18,000 BTUh to 100,000 BTUh




The NRCB is the first and only combination boiler on the market that can simultaneously provide domestic and space heating for residential applications. These simultaneous capabilities are easy to control and especially beneficial for applications that do not store or deliver heat energy efficiently. A user can, for example, take a shower without worrying about experiencing a corresponding drop in room temperature.

Another industry first is the NRCB’s use of 316L stainless steel primary and secondary heat exchangers, which have higher corrosion resistance than traditional heat exchangers for increased durability and lifespan. A third flat plate heat exchanger for domestic water heating is also made of stainless steel.

It also far exceeds the toughest emissions standards. The unit’s fully modulating burner has a nitrogen-oxide emissions level of only 14 parts per million (ppm), far below the South Coast Air Quality Management District requirement of 20 ppm.