Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4865539 | Fuel control unit for a gas furnace and method of making the same | — | 1989-09-12 |
| 4856983 | Hot surface direct ignition system for gas furnaces | — | 1989-08-15 |
| 4836770 | Primary gas furnace control | — | 1989-06-06 |
| 4809128 | Heating element operating unit and method | — | 1989-02-28 |