Wire Arc Directed Energy Deposition (Wire Arc DED) is an enticing chapter in metal layer-by-layer additive manufacturing processes. Wire Arc DED has attracted more research interest in the past decade, particularly low alloyed steel depositions garnering more recently broad appeal for structural, shipbuilding and offshore applications. The process however needs to be optimized to eliminate the inhomogeneity in material performance and microstructure observed in as-deposited conditions. In this work, multiple thin-walled depositions were made with ER70S-6 (low alloyed steel) feedstock by varying the heat input during the deposition. A thermocouple was placed in-between deposition for in-situ temperature measurement to understand the evolution of thermal history for a particular layer. Microstructural characterization and mechanical testing were performed on different depositions to understand the influence of heat input on different depositions. Thermal measurements revealed increasing peak temperature and cooling time with increasing heat input during deposition. This is reflected in the coarsening of grains and variation in hardness measured across the build direction for depositions made with higher heat input. Mechanical testing also reveals a decrease in strength for the sample deposited with higher heat input.