In certain combustion models, an initial temperature profile will develop into a combustion wave that will travel at a specific wave speed. Other initial profiles do not develop into such waves, but die out to the ambient temperature. There exists a clear demarcation between those initial conditions that evolve into combustion waves and those that do not. This is sometimes called a watershed initial condition. In this paper we will show that there may be numerous exact watershed conditions to the initial-Neumann-boundary value problem ut= Duxx+ e-1/u- σ(u-α), with ux(0, t) = ux(1, t) = 0, on = [0, 1]. They are composed from the positive non-constant solutions of Duxx+ e-1/υ- σ(υ-α) = 0, with υx(0) = υx(1) = 0, for small values of D. We will give easily verifiable conditions for when combustion waves arise and when they do not.