Homeowner Information - Furnace/AC


Your mechanical contractor is required to obtain a permit from the City of Creve Coeur for the installation of your replacement furnace or air conditioner. The city can issue this permit only to a mechanical contractor licensed by St. Louis County Department of Public Works. Visit the St. Louis County website for a list of licensed mechanical contractors. 

Below is a list of items reviewed by City inspectors to verify correct installation to ensure the safety, health and welfare of you and your family. A City inspection is required for all recently installed mechanical equipment (furnace and/or air conditioner).

To request a Final Inspection upon completion of the work, please call (314) 872-2500. The Building Division employees will work with your schedule. 

Please note: The City of Creve Coeur recommends you not make final payment to your contractor until the city has given your equipment final approval. Manufacturer’s installation guidelines and equipment specifications are required to be on site for inspection purposes. 

  1. Approved vent systems for gas-fired appliances shall be installed and terminated per the manufacturer’s installation guidelines. All vent systems shall be UL listed and labeled. Note: Installation of a Power Exhauster may require make-up air to be provided. Improper venting may lead to carbon monoxide poisoning.
  2. Draft requirements: New or existing chimneys or vents shall be sized or resized so as to develop a positive flow to convey combustion products to the outside atmosphere and to control flue gas condensation. Improperly sized chimneys or vents will not properly draft carbon monoxide to the outside.
  3. Each gas appliance shall have a gas shut-off valve (within 6 feet of the appliance in the same room) and a ground joint union between the appliance and the appliance shut-off valve. A sediment trap is required at each appliance. The shut-off valve allows replacement or repair of an appliance without turning off the gas supply to the entire house. The sediment trap extends the life of your appliances.
  4. The annular gap around any pipe or vent shall be properly fireblocked at any floor or ceiling level it penetrates. In case of a fire, fireblocking helps to prevent the spread of fire/gases throughout your home through concealed spaces.
  5. Gas piping identification. For other than black steel pipe, exposed piping shall be identified by a yellow label marked “GAS” in black letters. The marking shall be placed at intervals not exceeding 5 feet. The marking shall not be required on piping located in the same room as the equipment served. Gas piping materials shall meet the testing standards listed in the mechanical code and fuel gas code. Many pipe materials are not permitted to be used as gas piping.
  6. Fuel-burning appliances shall be provided with combustion air as required by the manufacturer’s specifications or mechanical code. The mechanical code requires that 50 cubic feet of combustion air be provided per 1,000 Btu/h of the aggregate input rating of all gas-fired appliances located in the mechanical room. Combustion air shall not be drawn from a bedroom, bathroom or storage closet.Direct vent appliances that do not draw combustion air from inside the building are exempt from these requirements. A lack of combustion air results in incomplete combustion, which causes soot production, increased carbon monoxide production, serious appliance malfunction and the risk of fire or explosion.
  7. Outside opening protection. Air exhaust and intake openings that terminate outdoors and serve high efficiency furnaces shall be protected with corrosive-resistant screens, louvers or grilles having a minimum opening size of ¼ inch and a maximum opening size of ½ inch in any dimension. Check manufacturer’s requirements. These items help to keep birds and rodents out of the vent pipes.
  8. Air conditioner leveling pads. Manufacturers require exterior condenser units to be placed on a level support pad. A support pad that is out of level can shorten the life of your air conditioner.
  9. Air conditioner’s electrical circuit breaker shall be properly sized. Properly sized circuit breakers or fuses protect your home’s wiring and appliance in case of a power surge or malfunction.
  10. The installation of any new electrical wiring shall require the issuance of an electrical permit from St.Louis County Department of Public Works.