Specifications

LWLCWH COLUMBIA BOILER COMPANY REV. 13106

than that of the primary LWCO. This relay must be manually reset if power is interrupted to the con-

trol circuit for any reason. During operation, if the water level falls below the probe rod, the energized

circuit breaks, causing the relay to open, disconnecting power to the burner. Restore the water level

to the normal operating level, then manually reset the control to resume operation.

The most common optional equipment includes the McDonnell & Miller 42 Series Pump Control and

Low Water Cut-Off and the McDonnell & Miller No. 247-2 Feeder Combination. These controls are

mounted on the left side of the boiler using the 1" tappings found in the side and on top of the boil-

er, as part of an equalizing line. These devices may be used as a primary or secondary LWCO. Both

controls use a float activated switch to control LWCO and pump control functionality.

For additional information on the appropriate Low Water Cut-Off, see the LWCO cut sheets following

this booklet.

Safety Valve

Safety valves shall be piped so that any discharge cannot cause injury to people or damage to prop-

erty. The discharge piping must be supported so that the weight of the piping is not transmitted to the

safety valve body. The weight supported by the valve outlet should not exceed that of a drip pan

elbow. Installations requiring long discharge piping should not be connected directly to the safety

valve. Refer to Drawing PL-049 in the Appendix.

In order to achieve the topmost performance and maximum safety valve life, maintain a proper oper-

ating gap between the set pressure of the safety valve and the maximum operating pressure of the

boiler.

If the valve discharges on its own, contact a qualified service technician to determine the cause. This

may be an indication of equipment or system malfunction.