Discover the most innovative line of electronic low water cut off devices available today, including the world's first configurable device.
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This year marks 100 years of McDonnell & Miller as a leader in engineering and manufacturing safety devices for steam and hot water boilers.
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Introducing the GuardDog® RB-122E, a sturdy, reliable primary cut-off device for residential and commercial hot water boilers.
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Introducing the GuardDog® RB-24SE, which packs a whole lot of control into a compact device, making it ideal for tight spaces.
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More efficiency in a smaller footprint.
Reduced costs plus worry-free reliability.
100 years of dependability and innovation.
A full line of flow switches.
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