Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1346 - MINNESOTA MECHANICAL AND FUEL GAS CODES
MINNESOTA MECHANICAL CODE
Part 1346.1007 - SECTION 1007 BOILER LOW-WATER CUTOFF

1. An automatically fired hot water boiler or group of boilers piped together having a rated input of 400,000 Btu/hr (117 kW) or above shall be equipped with an automatic low-water fuel cutoff to stop the combustion operation when the water level drops below the lowest safe permissible water level established by the boiler manufacturer.

2. A boiler installed at an elevation where all radiation in the system is below the lowest safe permissible water level shall be equipped with an automatic low-water fuel cutoff to stop the combustion operation when the water level drops below the lowest safe permissible water level established by the boiler manufacturer.

3. A low-water fuel cutoff shall be installed when recommended by the manufacturer's installation instructions or listing and when special consideration and installations will require a low-water fuel cutoff to protect a hot water or steam boiler.

4. A means shall be provided for testing the operation of the low-water fuel cutoff without requiring the entire system to be drained.

5. A watertube or coil-type boiler requiring forced circulation to prevent overheating of the tubes or coils shall have a flow-sensing device installed, in lieu of the low-water fuel cutoff, to automatically stop the combustion operation when the circulating flow is interrupted.