A breathing assistance apparatus for the delivery of breathing gas to a user, wherein the apparatus comprises: a heating element for heating a humidification chamber; a control system comprising a first electronic protection circuit connected to the heating element and comprising: a first temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a first comparator circuit; a first switching member; and a programmable control unit; where the first comparator circuit is configured to receive outputs from the first temperature sensor and compare those outputs with a first predetermined temperature threshold T1 to determine if the heating element temperature exceeds the first predetermined temperature threshold T1 and to cause the first switching member to disable power to the heating element when the sensed heating element temperature exceeds the first predetermined threshold temperature TI; and where the programmable control unit is configured to receive outputs from the first temperature sensor and to cause the first switching member to disable power to the heating element when the sensed heating element temperature exceeds a first predetermined programmed threshold temperature, which may be equal to or greater than T1; characterised in that: the control system comprises a second electronic protection circuit comprising: a second temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a second comparator circuit; and a second switching member; the second comparator circuit is configured to receive outputs from the second temperature sensor and compare those outputs with a second predetermined threshold temperature T2 to determine if the sensed heating element temperature exceeds the second predetermined temperature threshold T2 and to cause the second switching member to disable power to the heating element when the sensed heating element temperature exceeds the second predetermined threshold temperature T2, which may be equal to or greater than T1; and the control unit is configured to identify the difference in outputs of the first and second temperature sensors (710, 720) and to cause at least one of the first and second switching member(s) (730, 740) to disable power to the heating element when the control unit identifies that the outputs of the first and second temperature sensors differ by a predetermined threshold. a heating element for heating a humidification chamber; a control system comprising a first electronic protection circuit connected to the heating element and comprising: a first temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a first comparator circuit; a first switching member; and a programmable control unit; a first temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a first comparator circuit; a first switching member; and a programmable control unit; where the first comparator circuit is configured to receive outputs from the first temperature sensor and compare those outputs with a first predetermined temperature threshold T1 to determine if the heating element temperature exceeds the first predetermined temperature threshold T1 and to cause the first switching member to disable power to the heating element when the sensed heating element temperature exceeds the first predetermined threshold temperature TI; and where the programmable control unit is configured to receive outputs from the first temperature sensor and to cause the first switching member to disable power to the heating element when the sensed heating element temperature exceeds a first predetermined programmed threshold temperature, which may be equal to or greater than T1; characterised in that: the control system comprises a second electronic protection circuit comprising: a second temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a second comparator circuit; and a second switching member; a second temperature sensor to sense the temperature of the heating element and produce outputs based on the sensed heating element temperature; a second comparator circuit; and a second switching member; the second comparator circuit is configured to receive outputs from the second temperature sensor and compare those outputs with a second predetermined threshold temperature T2 to determine if the sensed heating element temperature exceeds the second predetermined temperature threshold T2 and to cause the second switching member to disable power to the heating element when the sensed heating element temperature exceeds the second predetermined threshold temperature T2, which may be equal to or greater than T1; and the control unit is configured to identify the difference in outputs of the first and second temperature sensors (710, 720) and to cause at least one of the first and second switching member(s) (730, 740) to disable power to the heating element when the control unit identifies that the outputs of the first and second temperature sensors differ by a predetermined threshold.