Safety pressure switch

Abstract

A safety pressure switch can be used with a gas appliance. The gas appliance can be a single fuel or a dual fuel appliance for use with one of a first fuel type or a second fuel type different than the first. The safety pressure switch can be fluidly connected to a fuel input and electrically coupled to a pilot assembly.

What is claimed is: 
     
         1 . A heater assembly for use with one of a first fuel type or a second fuel type different than the first, the heater assembly comprising:
 a burner;   a pressure regulator unit configured to regulate either a fuel flow of a first fuel type within a first predetermined range or of a second fuel type within a second predetermined range different from the first, the pressure regulator unit comprising a housing having first and second fuel hook-ups, the first fuel hook-up for connecting the first fuel type to the heater assembly and the second hook-up for connecting the second fuel type to the heater assembly;   a pilot nozzle;   a temperature sensor;   a control valve for controlling the flow of said first type of fuel and the flow of said second type of fuel to said burner;   a pressure switch communicating with one of said first and second fuel hook-ups, wherein when fuel has a pressure below a threshold said pressure switch permits said temperature sensor to electrically connect with said control valve and when a fuel has above said pressure threshold said pressure switch prevents said temperature sensor from electrically connecting with said control valve.