INSTRUCTION MANUAL
MM-315H
210424
• Before using this product read and understand instructions.
• Save these instructions for future reference.
• All work must be performed by qualified personnel trained in the proper application,
installation, and maintenance of plumbing, steam, and electrical and/or systems in
accordance with all applicable codes and ordinances.
• To prevent serious burns, the boiler must be cooled to 80°F (27°C) and the pressur emust be
0 psi (0 bar) before servicing.
• To prevent electrical shock, turn off the electrical power before making electrical
connections.
• This low water cut-off must be installed in series with all other limit and operating controls
installed on the boiler. After installation, check for proper operation of all of the limit and
operating controls, before leaving the site.
• We recommend that secondary (redundant) Low Water Cut-Off controls be installed on all
steam boilers with heat input greater than 400,000 BTU/hour or operating above 15 psi
of steam pressure. At least two controls should be connected in series with the burner control
circuit to provide safety redundancy protection should the boiler experience a low water
condition. Moreover, at each annual outage, the low water cut-offs should be
dismantled, inspected, cleaned, and checked for proper calibration and performance.
• Boiler manufacturer schematics should always be followed. In the event that the boiler
manufacturer’s schematic does not exist, or is not available from the boiler manufacturer, refer
to the schematics provided in this document.
• To prevent a fire, do not use this low water cut-off to switch currents over 10.2A, 1/2 HP at
120 VAC or 5.1A, 1/2 HP at 240 VAC, unless a starter or relay is used in conjunction with it.
• This product can expose you to chemicals including Lead and Hexavalent Chromiun, which are
known to the State of California to cause cancer and birth defects or other reproductive harm.
For more information go to: www.P65Warnings.ca.gov.
