Abstract: The present invention is a method and apparatus for changing fuels used in a heating system without substantially recycling the heating system where a main flame burns fuel supplied to the heating system. A fuel changeover signal is received from a fuel selector. Flow of a first fuel to the heating system is regulated in response to the fuel changeover signal to achieve a low fire state in the heating system. A pilot flame is established in the heating system and flow of the first fuel is shut off. A fuel indicator signal is received from the fuel selector indicating a desired fuel. The main flame in the heating system which is burning the first fuel is extinguished. The pilot flame is monitored for stability and the main flame is re-established in the heating system burning the desired fuel in response to the fuel indicator signal.

Abstract: A method and apparatus control firing rate in a heating system to compensate for thermal mass characteristics of the heating system. The thermal mass characteristics of the heating system are derived from heating system identification information. A weighted control response factor is selected which is representative of load characteristics of a load type affecting firing rate control and which is representative of desired control tightness. The firing rate is varied, based on the weighted control response factor and the thermal characteristics, to match the heating system, the load type being controlled and the desired control tightness for optimum control.

Abstract: A method and apparatus monitor fuel pressure in a heating system where a controller controls actuation of fuel valves. A fuel pressure limit signal is provided to the controller for determining if the fuel pressure crosses predetermined thresholds. In order to avoid nuisance shut-downs, the fuel pressure limit signal is ignored by the controller for a predetermined time interval after the controller has actuated a fuel valve.

Abstract: A method of making an enamel bead and resulting bead which includes the provision of a short length of copper tubing forming a bead core member wherein the copper tubing is heated to a red hot state and rolled in copper enamel flux one or more times to coat the tubing following which the flux coated tubing is again heated to a red hot state and rolled in particulate enamel material to coat the tubing externally with enamel material, then heating the enamel material coating until it melts and is distributed throughout the tubing outer surface in the desired bead configuration and finally cooling the enamel coating to form a highly durable bead having a copper tubing core with an outer layer of enamel of a selected color.