David Aaskov Inc. Plumbing, Heating & Air Conditioning is a small company founded in 1977. Presently we have 3 employees and specialize in Natural & Propane Heating upgrades for homes, apartments and businesses. We are suppliers and installers of air source heat-pumps and hot water systems. Upgrades from older R-22 Compressors and evaporators to modern "Higher Efficiency" 410A Heat Pumps with evaporators TX valves. Upgrades from single phase motors in larger air handlers to 3 phase motors controlled by a VFD (Variable Frequency Drive). Replacement of tankless oil boilers with modern triple pass design (energy star rated). Installers of tankless gas water heaters.