Issued Patents All Time
Showing 1–15 of 15 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7513221 | Water heater with pressurized combustion | Ray O. Knoeppel | 2009-04-07 |
| 7421784 | Method of manufacturing a water heater with a leak detection system | William Hoover | 2008-09-09 |
| 7316206 | Water heater with noise attenuation | Hyungsik Lee | 2008-01-08 |
| 7032543 | Water heater with pressurized combustion | Ray O. Knoeppel | 2006-04-25 |
| 6679014 | Rooftop water heater | Dennis R. Hughes, Kevin Field, Randy T. Meyer | 2004-01-20 |
| 6591788 | Rooftop water heater | Dennis R. Hughes, Kevin Field, Randy T. Meyer | 2003-07-15 |
| 6532906 | Inlet heat recovery module for water heater | Ray O. Knoeppel | 2003-03-18 |
| 6422179 | Water heater flue system | Dennis R. Hughes, Kevin Field, Robert F. Poehlman | 2002-07-23 |
| 6286465 | Water heater flue system | Dennis R. Hughes, Kevin Field, Robert F. Poehlman | 2001-09-11 |
| 6283067 | Potable water temperature management system | — | 2001-09-04 |
| 6202935 | Combined potable water heater and hydronic heating system | Jill M. Szczech, Frank A. Mueller, Dennis R. Hughes, Kevin Field, Ray O. Knoeppel +1 more | 2001-03-20 |
| 4953510 | Apparatus and method for heating water | Kenneth R. Walther | 1990-09-04 |
| 4951614 | Water heater construction | Dennis R. Hughes | 1990-08-28 |
| 4911108 | Water heater construction | Dennis R. Hughes | 1990-03-27 |
| 4817564 | Water heater construction | Dennis R. Hughes | 1989-04-04 |