When you purchase a high-efficiency propane dryer.
When you purchase a high-efficiency propane cooktop or range.
When you purchase a vented room heater or wall furnace.
When you purchase a duel fuel heat pump with propane as one fuel.
When you purchase a propane furnace.
When you purchase a propane gas pack.
When you purchase a propane storage-tank water heater.
When you purchase a propane tankless water heater.