Performed heater tune-up on one Carrier and one Trane gas furnace systems. Also performed a heater tune-up on a Mitsubishi Mini Split system. Checked the electrical, mechanical and performance systems of the units. Cleared, cleaned, flushed and treated the drain lines. Cleaned the exterior of the furnace systems and washed the mini split outdoor coil. All air purifiers and surge protection devices are working. No major issues were found. All systems are operational at this time.