An improved boiler apparatus having multiple resistive heating elements are provided with fixed resistances that can be rewired to allow dual voltage capability and at the same time, reduced watt density. For 120V operation, the large diameter 9-ohm coil is used alone to provide the lowest possible watt density. For 240V operation, all three heating coils are wired in series, creating a low watt density but high wattage heater.

An improved boiler apparatus having a removably couplable heating element that can have resistive heating elements are provided with fixed resistances that can be rewired to allow variable wattage usage of the heating element. Some heating element assemblies can include more than one heating coils or heating element. The heating elements can be wired in series, or parallel thereby creating a low watt density but high wattage heater.

An improved boiler apparatus having a removably couplable heating element that can have resistive heating elements are provided with fixed resistances that can be rewired to allow variable wattage usage of the heating element. Some heating element assemblies can include more than one heating coils or heating element. The heating elements can be wired in series, or parallel thereby creating a low watt density but high wattage heater.

The disclosed technology includes a controller for a cascade boiler system having both condensing and non-condensing boilers. The controller can receive supply water temperature data and return water temperature data to determine a current temperature differential in the system. The controller can determine a current load demand value using the current temperature differential and a set point temperature. If the current load demand value is less than or equal to a first load demand threshold, the controller can output a control signal for a condensing boiler to transition to a heating mode. If the current load demand value is greater than a second load demand threshold, the controller can output a control signal for a non-condensing boiler to transition to a heating mode.

An electrode boiler control apparatus includes a control circuit formed in an electrode boiler in which an intake electronic valve and an exhaust electronic valve in addition to an intake control valve and an exhaust control valve corresponding to air control valves formed at both sides of an upper portion of the electrode boiler, connected to the intake electronic valve and the exhaust electronic valve to control the intake electronic valve and the exhaust electronic valve; a current controller connected to a current transformer connected between electrode bars of the electrode boiler to control the current transformer; and a temperature controller connected to a temperature sensor formed on a hot water tank of the electrode boiler, and configured to control the temperature sensor and receive a temperature value measured by the temperature sensor.

An electrode boiler control apparatus includes a control circuit formed in an electrode boiler in which an intake electronic valve and an exhaust electronic valve in addition to an intake control valve and an exhaust control valve corresponding to air control valves formed at both sides of an upper portion of the electrode boiler, connected to the intake electronic valve and the exhaust electronic valve to control the intake electronic valve and the exhaust electronic valve; a current controller connected to a current transformer connected between electrode bars of the electrode boiler to control the current transformer; and a temperature controller connected to a temperature sensor formed on a hot water tank of the electrode boiler, and configured to control the temperature sensor and receive a temperature value measured by the temperature sensor.

The disclosed technology includes a controller for a cascade boiler system having both condensing and non-condensing boilers. The controller can receive supply water temperature data and return water temperature data to determine a current temperature differential in the system. The controller can determine a current load demand value using the current temperature differential and a set point temperature. If the current load demand value is less than or equal to a first load demand threshold, the controller can output a control signal for a condensing boiler to transition to a heating mode. If the current load demand value is greater than a second load demand threshold, the controller can output a control signal for a non-condensing boiler to transition to a heating mode.

A plasma heating apparatus including a boiler vessel for holding water to be heated, a cathode housed in the vessel, the cathode defining a watertight cathode chamber isolated from the water in the vessel, and, an anode housed in the cathode chamber, the anode including an internal passage for receiving a gas from outside of the vessel when the passage is connected to a gas supply, and wherein the anode is connectable to a power source for receiving power for generating a plasma in the cathode chamber. In another aspect, the present disclosure relates to a heat or power generating system or plant including the plasma heating apparatus.

An electrode boiler control apparatus includes a control circuit formed in an electrode boiler in which an intake electronic valve and an exhaust electronic valve in addition to an intake control valve and an exhaust control valve corresponding to air control valves formed at both sides of an upper portion of the electrode boiler, connected to the intake electronic valve and the exhaust electronic valve to control the intake electronic valve and the exhaust electronic valve; a current controller connected to a current transformer connected between electrode bars of the electrode boiler to control the current transformer; and a temperature controller connected to a temperature sensor formed on a hot water tank of the electrode boiler, and configured to control the temperature sensor and receive a temperature value measured by the temperature sensor.

An electrode boiler control apparatus includes a control circuit formed in an electrode boiler in which an intake electronic valve and an exhaust electronic valve in addition to an intake control valve and an exhaust control valve corresponding to air control valves formed at both sides of an upper portion of the electrode boiler, connected to the intake electronic valve and the exhaust electronic valve to control the intake electronic valve and the exhaust electronic valve; a current controller connected to a current transformer connected between electrode bars of the electrode boiler to control the current transformer; and a temperature controller connected to a temperature sensor formed on a hot water tank of the electrode boiler, and configured to control the temperature sensor and receive a temperature value measured by the temperature sensor.