Noritz CB199-DV - Low Water Cutoff (LWCO) Installation

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Low Water Cutoff
Chapter4.–Installation
Internal of the Combi Boiler
The Noritz Combi Boiler is equipped with a factory installed, pressure sensor type low water cutoff device.
The lowest operation pressure for this device is 8psi. (operation pressure = (default valve 12psi) - (4psi))
• The Combi Boiler performs water replenishment automatically when the built-in water pressure sensor detects insufcient
water level in the Combi Boiler system.
Extenal of Combi Boiler
• Low water cutoffs shall comply with the Safety Standard for Limit Controls, ANSI/UL 353, or the Standard for Temperature
Indicating and Regulating Equipment, CAN/CSA C22.2, No. 24, as applicable.The following gure illustrates an example of typical
LWCO installation.
• Install the probe above the minimum safe water level, as determined from the Combi Boiler manufacturer’s literature.
NOTE: This may be in a tapping on the Combi Boiler or in the Combi Boiler supply or return piping.
• Install the probe to extend into the Combi Boiler cavity or piping to make contact with the water.
• Low water cutoffs shall be located so as to provide adequate access for cleaning, repairing, testing and inspection.
• Remove the factory installed jumper on the LWCO terminals (CN22) prior to connecting the LWCO
• The Combi Boiler supplies 24 VAC from the terminal CN17 #5 and #6 (see below illustration).
4-6. Low Water Cutoff (LWCO)
<LWCO & Controller Connection>
LWCO
LWCO line
AC 24V
LWCO needs to be installed
above the top of casing