Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8327810 | High efficiency water heater | Donald E. Woollen | 2012-12-11 |
| 7614366 | High efficiency water heater | Donald E. Woollen | 2009-11-10 |
| 4798327 | Convection lock-vent | — | 1989-01-17 |