Low Water Cutoff Control for Maintaining a Safe Water-Level in your Boiler

The low water cutoff control is the most important electrical/mechanical device on your boiler for maintaining a safe water-level.

The low water cutoff control is generally a float operated or probe operated control that is set to de-energize the burner limit circuit and shut down the burner upon LowWaterControls_TechTalkIMGdetecting a low water condition in the boiler. Another function is to sound the low water alarm at the same time the burner is shut down. A pump on-off control can start and stop the boiler feed pump to maintain water at safe operating level in boiler. One additional function may be added to the control is a high water alarm.

If a low water condition develops, it could lead to serious potential problems. The low-water cutoff should be tested at least weekly.

  • It is a well established fact that low water cutoffs are not always properly maintained. Click here for McDonnell & Miller’s Product Bulletin Proper Maintenance of Low Water Cutoff’s
  • Click here for McDonnell & Miller’s Recommended Replacement Schedules
  • Another Article on the National Board of Boiler Inspectors website, Low Water Cutoff Technology, contains a handy section called “Potential Failure Modes – What to Watch For”

Are your controls out of date? Contact your Aftermarket or Parts salesperson to make sure your system is in safe operating condition.