Cracked Heat Exchanger in a gas furnace. A.I.R is committed to properly inspecting your heating system by using Oklahoma Natural Gas’s 26-point Heating System Checkup list. The checkup insures your system is operating safely and as designed with minimal energy waste. And A.I.R. will also conduct a video inspection of your heat exchanger for cracks and leaks to prevent carbon monoxide poison in your home – Free of Charge. ONG is offering a $30 rebate to all it’s customers for having the checkup performed by a licensed HVAC contractor. A.I.R. is a licensed and listed contractor for this service and will assist all customers in the preparation of the paperwork for a prompt rebate reimbursement. Call 405-618-2247 to schedule your 26-point checkup today for safety and savings! * ONG is offering the rebate $ until the allotted rebate funds are depleted. First come first serve basis will be used to determine who receives the rebate.