Systems Help Center

This installation, operation, and maintenance manual from Dunham-Bush contains information about the Vari-Vac DTS-2 Programmable Timer. Thanks to Brad White for finding a...

This document contains information about the VECO vapor heating system, the very best offering of the Vapor Engineering Company, circa 1930. It's always a joy to find one...

Here's the whole Warren Webster line from 1943, along with some very clear explanations of how their heating system worked. After the catalog material, you will find the ...

This article by Henry H. Aronson about venting unit heaters appeared in Heating, Piping & Air Conditioning magazine. Thanks to T.P.

This patent contains the very best description of a water seal trap's role in vapor heating. This is courtesy of Steve Pajek. 

These tests were made during the winters of 1943-44 and 1944-45. The goal was to find a hydronic system that would work well in homes without basements, which were antici...

Bell & Gossett's Air Control Booster Package was a product that never really took off. The circulator removed the air from the system. This brochure is from 1966.

Here is an informational brochure about the Utica Heating system from The Royal Heating Company that appeared in 1938. Thanks to John Mills for scanning it and sharing it...

Thanks to Steve Pajek for finding this patent issued in 1915. Honeywell was not the only company with a heat generator!

This device from the D & T Manufacturing Co. is a strainer, pressure-reducing valve, bypass valve, and relief valve, all combined in one unit. Hot stuff for the time!