A model for microwave heating of electron rings in the ELMO Bumpy Torus configuration is analyzed using a relativistically correct quasi‐linear formulation. The spatial locations of heating by the different electron‐cyclotron harmonics are calculated. The steady‐state ring energy and the microwave power required to sustain the rings are determined by balancing the line‐averaged heating rate against classical collisional and radiative energy loss processes. Although ring formation is generally attributed to the second harmonic electron‐cyclotron resonance, the calculations show that fundamental heating also plays a critical role in ring start‐up and steady state. The model predicts ring power requirements for EBT which are consistent with previous estimates.