System and method for draft safeguard
US6851948B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2003 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Jun 29, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N2223/08
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A gas furnace responsive to a thermostat includes a thermal switch wired in series between the furnace power supply and the thermostat. A microprocessor connected to the thermal switch detects when the switch opens and closes, carrying out prearranged programs in response thereto. The thermal switch is mounted so that it opens when an over-pressure in the furnace draft system is detected, as evidenced by hot flue gasses passing over the thermal switch probe. The switch is allowed to cycle at least one time before the furnace is disabled. After a certain period of the time, the combustion cycle is reinitiated and the above steps are repeated if the thermal switch again resets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.