We're the Geothermal Source in San Marcos! San Marcos people in the know turn to Southwest Mechanical Services for all their geothermal heating and cooling needs. They place their confidence in us to provide not only the correct installation and service but also the knowledge to help them maximize the potential from their geothermal systems. Considering a geothermal system of your own? Give our nifty little Geothermal Savings Calculator a try. Just load it with your data and stand in awe of the results. Then, contact us, the San Marcos, Texas, geothermal professionals at Southwest Mechanical Services.