A Multi-Functional Heat Pulse Probe (MFHPP) for vadose zone measurements was developed and tested in the laboratory. The probe combines a heat pulse technique for estimating soil heat properties, water flux, and water content with a Wenner array measurement of Electrical Conductivity (EC). The probe thus provides a simultaneous estimate of water, heat, and solute transport parameters at the same location and spatial scale. Using an integrated circuit within the probe body, pre-and postprocessing of the data occurs real time. To test the MFHPP, highly controlled steady-state flow column experiments in sand were conducted over a wide range of saturations, flow velocities, and EC concentrations. The data were analyzed using the modified HYDRUS model, which includes an option for inverse modeling of simultaneous water, vapor, heat, and solute transport. The inverse estimated parameters included volumetric heat capacity, thermal conductivity, heat dispersion, water flux, moisture content, and solute dispersion. The performance of the MFHPP was compared and evaluated with independently measured data. Thermal properties, including thermal conductivity and thermal diffusivity, compared well with previously measured data for the sand. The MFHPP probe constitutes a new promising technique for combined water, solute and heat transport measurements in the vadose zone.