A well heater is provided, the heater effective for heating earth surrounding a wellbore from the wellbore, the well heater including: a) a resistive heating element, the resistive heating element traversing a segment of the wellbore to be heated; b) more than one ceramic insulators, the ceramic insulators defining a channel through which the resistive heating element passes; and c) a support element connected to at least one ceramic insulator, the support element effective for conducting heat from the ceramic insulator and radiating heat to the wellbore wall, and to support the weight of the electrical resistance element and the ceramic insulators through the connection to the at least one ceramic insulator. The wellbore heater of the present invention is easily fabricated from available materials, and provides a reliable and inexpensive wellbore heater.