Method for proving furnace high-heat pressure switch
US5522541A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1994 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Oct 12, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N2237/10
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
In a two-stage furnace system, including a thermostat, at least one gas burner with a low and high-fire operating capability, an inducer fan having low and high speed operating settings, and a high-fire pressure switch, a method for handling the high-fire pressure switch being in an inappropriately open condition. The method has the steps of: determining whether the thermostat is issuing a call for high heat and, if it is, determining if the high-fire pressure switch is open. If the high-fire pressure switch is open, waiting a predetermined time, determining if the high-fire pressure switch is still open and, if it is, completing a furnace shutdown procedure, then initiating a normal shutdown, then an ignition sequence in high-speed inducer pre-purge mode, determining if the high-fire pressure switch remains open, and if so, running at least one gas burner in low-fire mode. If, while these steps are being performed, the high-fire pressure switch closes, running the system in high-fire mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.