Granted Patent
Utility
US 5,666,944 · App. 08/524,001
Water heating apparatus with passive flue gas recirculation
Inventor:
Mark A. Ferguson
Patented Case
View Patent ↗
Granted: Sep 16, 1997
Filed: Sep 5, 1995
Inventor
Mark A. Ferguson
Assignee (at issue)
PVI Industries, LLC
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.