Systems Help Center

This circa-1950 brochure features Radiator Heat Plus Taco-Trol for Hot Water Heating Systems from Taco Heaters, Inc. It reads, "The Taco-Trol is a combination hot water h...

This is a patent that Gil Carlson received for a drain and vacuum breaker valve in 1957.

Honeywell tells the story of their Aquastat in this document. It is not dated, but is probably from the 1950s.

Here is a 1909 patent for an unusual, and very creative, regulator from J.M. Dougherty & H.C. Tabler.

The Honeywell Air-Seal Generator is a turn-of-the-century offering from Honeywell. It is similar to their Heat Generator. Thanks to Alex Marx for scanning this brochure f...

After moving the gravity-hot-water-system expansion tank from the attic to the basement, The Stack Heater Company introduced a heating system that didn't need a tank at a...

Here instructions for the Thrush Flow Control Valve from the H.A. Thrush & Company. Thanks to Mike Zydiak for finding and sharing this document with us.

H. A. Thrush & Company of Peru, Indiana published this book for contractors about the Thrush System of Hot Water Heating.

Before circulators arrived, heating contractors tried some very interesting things to get the water to flow where they wanted it to flow. Here's a good example of that fr...

This article about calculating floor types for radiant heating systems first appeared in Plumbing & Heating Business magazine in September 1941.