Everything You Need To Know About McDonnell & Miller Products

Who is McDonnell & Miller?

An industry leader in the engineering and manufacturing of flow switches, low water cut-offs and water feeders for over 80 years, McDonnel & Miller specializes in keeping all kinds of boilers running safely. The boiler is the most important part of a central heating system. If you have a hydronic or a steam heating system, chances are you are currently using a product sold by McDonnell & Miller, or a product in the same category as the items that they sell.

120V Low Water Cut-off(Water)
– Electronic operation
– Residential applications
– Electronic
– Hot Water Boilers

What products do they make?

Boiler Controls, Flow Switches, Liquid Level Controls, Valves and Water Feeders, all associated with protecting your boiler from various issues that could happen in case of emergency. The low water cutoff and the water feeder are both required on steam systems, and work hand-in-hand to ensure that the boiler remains at the proper water level to safely run. Water feeders monitor water level and allow the boilers water line to rise and fall, while the low water cut off works like anti-lock brakes to help prevent accidents if it detects a drop in liquid levels. If the water level drops below a safe operating condition, it will shut off fuel to the fire.

Flow switch W/ NEMA 1 enclosure
– Replacement for common flow switches from Johnson/Penn, Taco, Watts
– 1″ NPTM Pipe Connection
– 1″, 2″, 3″ & 6″ (25, 50, 80, & 150mm)
– EPDM O-ring sealed

Flow switches, on the other hand, are required in electric heating systems, but can be used for any number of applications. They ensure that the boiler cannot fire while the system is dry or low on water. They monitor the flow of air, steam or liquid and send a trip signal to a different device in the system. Used for protection, they complete or break the circuit they are wired to.

Do they have the part that I need?

If you are looking for a product to increase your boiler safety and level control, McDonnell and Miller products can most likely fulfill your needs. They also carry many replacement parts for many common brands such as Johnson/Penn, Taco, Watts, etc.

How do they maintain the best possible quality?

In order to create an atmosphere of trust, McDonnell & Miller is certified as an ISO 9001 and ISO 14001 supplier. This means they are a model for quality assurance in design, development, production, installation and servicing. Recognition as ISO 9001 lets their customers know that there is a certified quality management in place, that spans internationally. ISO is an international organization for standardization, creating standards that span across 165 member countries to facilitate international trade.

General purpose flow switch w/ NEMA 4 enclosure – For Liquid Flow – 1″ NPTM Pipe Connection	24V Low Water Cut-Off – (Water) – Electronic – Hot Water Boilers – Residential applications	Uni-Match Universal Water Feeder (24V) – Steam Boilers – Water supply pressures to 150 psi – Boiler pressures to 15 psi