Phelan furnace installation is propane-only work because SoCalGas natural gas service does not extend to most of Phelan or Pinon Hills. Propane furnace installation differs from natural gas in three ways: orifice sizing (propane orifices are smaller because propane delivers more BTU per cubic foot), regulator work (propane uses two-stage regulators stepping tank pressure to burner pressure), and tank-supply diagnostics during install commissioning. We are equipped for propane installs and stock propane parts on every Phelan dispatch. Cold-snap performance at 3,800 ft elevation matters more than at valley elevations. Winter overnight lows in Phelan and Pinon Hills hit the high teens regularly, which stresses heat exchangers more than mild winters and makes equipment reliability a higher priority. We recommend 90%+ AFUE high-efficiency systems on every Phelan install for the cold-snap reliability benefit (better modulation handles cold-start cycles more gracefully than single-stage 80% AFUE) and for lower propane consumption. Liberty Utilities runs propane rebate programs where applicable that we pull at quote time.