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Product Spotlight


For accurate and dependable boiler protection, Taco's Low Water Cutoff (LWCO) features the simplicity, reliability and unmatched quality you’ve come to expect from Taco Electronic Controls. The LWCO is a probe style, microprocessor based control that detects the fluid level in hot water and steam boilers. Probe sensitivity is adjustable, thanks to a new patent pending technology, and external LEDs and simplified wiring make installation and testing a snap.


The Taco LWCO provides reliable protection for all types of boilers, from small residential hot water boilers to large industrial steam boilers. The boiler’s minimum safe operating water level is specified by each manufacturer. Should the water level dip below that specified level, heat will accumulate quickly causing significant damage to the boiler and a potential external safety hazard. The Taco LWCO prevents this hazard from occurring. 

The LWCO can act as either the primary or secondary low water cutoff on low-pressure steam boilers, the primary limit control on hot water boilers or to protect pumps from running dry in condensate receiver tank applications. The LWCO can also activate alarm systems or automatic water feeders.


Probe Style LWCO

A probe uses the boiler’s water to complete an electrical circuit. As long as water covers the probe, the electronic circuit will be maintained. If the water level drops below the probe, the circuit is broken, shutting down the burner and protecting the boiler. 

Normal operation Low water condition In a low water situation, if the burner continues to fire, damage can occur to the boiler and create a potential disaster. A Taco Low Water Cutoff turns off the burner
and signals that a low water situation has occurred.

Choosing The Right Type
With two basic controls, Taco has simplified the process of choosing the right one. Our LT models include an external test button, adjustable Delay On Break (DOB) and a Delay On Make (DOM) feature; our LN models do not. DOB keeps the burner lit for up to 60 seconds after the probe stops sensing water. DOM allows up to a 15-second delay before firing the burner once water has come in contact with the probe. Generally, LT models will be used on larger hot water boilers and all steam boilers; LN models will be used on smaller residential hot water boilers (under 400,000 BTU). Consult your local inspector for applicable codes.

Customize for your Installation 
Choose LT or LN, then add the features you need. 

Automatic Reset Mode
A red LED indicates a low water condition. When the water level reaches a safe level, the boiler will automatically resume normal operation. The LWCO control may be used in conjunction with an automatic water feeder to keep the boiler filled to the proper level. Adjustable DOM and DOB settings are standard on all LT series auto reset models.

Manual Reset Mode 
The red LED indicates a low water condition. When a low water condition occurs, the Manual Reset Button must be pressed to resume boiler operation once the proper water  level has been restored. The control may be used in conjunction with an alarm. DOM settings are disabled.  

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