A portable heater comprising a housing composed of separate parts including a lower part having a bottom and side wall portions defining a trough, components of said heater including a combustion chamber assembly and a support, said support positioning in a sense transverse to said lower part, said combustion chamber assembly and said support having in connection therewith means for seating to and interfitting with means in connection with said side wall portions of said lower part in a drop fit thereof to said lower part, said support mounting thereon a motor and a fan blade assembly for powering said heater and developing therein a pressured flow of air to and about said combustion chamber assembly and means for delivering fuel and igniting the fuel in delivery thereof to the combustion chamber of said assembly, said interfitting means being constructed and arranged to position said combustion chamber assembly and said support and said fan blade assembly in a substantially direct alignment on and within said lower part of said housing and to inhibit relative longitudinal and lateral motion therebetween.