Pennsylvania Code
Title 67 - TRANSPORTATION
Part I - Department of Transportation
Subpart A - Vehicle Code Provisions
Article VII - Vehicle Characteristics
Chapter 171 - SCHOOL BUSES AND SCHOOL VEHICLES
Subchapter C - SCHOOL BUS BODY STANDARDS
Section 171.54 - Heaters

(1) Heaters shall provide evenly distributed heat throughout the interior of the bus.

(2) At least one heater shall provide defrosting for the windshield, driver's side sash and entrance door.

(3) Heater hoses shall be adequately supported to guard against excessive wear due to vibration. The hoses may not dangle or rub against the chassis or sharp edges and may not interfere with or restrict the operation of any engine function. Heater hoses shall conform to applicable SAE Standards. See Appendix A. Heater lines on the interior of the bus shall be shielded to prevent scalding of the driver or passengers.

(4) A hot water heater system shall include a shutoff valve installed in the pressure and return lines at the engine. There shall be a water flow regulating valve installed for convenient operation by the driver. Type A school buses are exempt from this paragraph.

(5) Accessible bleeder valves shall be installed to remove air from the heater lines. The valves shall be installed in an appropriate place in the return lines of the heater.

(6) Heater motors, cores and fans shall be readily accessible for service. Access panels shall be provided as needed.

(1) The auxiliary heating system fuel shall utilize the same type fuel as specified for the vehicle engine.

(2) The heaters may be either of a direct hot air type or connected to the engine's coolant system.

(3) An auxiliary heating system, when connected to the engine's coolant system, may be used to preheat the engine coolant or preheat and add supplementary heat to the bus's heating system.

(4) Auxiliary heating systems shall be installed pursuant to the manufacturer's recommendations and may not direct exhaust in a manner that will endanger bus passengers.

(5) Auxiliary heating systems which operate on diesel fuel shall be capable of operating on #1, #2 or blended diesel fuel without the need for system adjustment.

(6) Auxiliary heating systems shall be low voltage.

(7) Auxiliary heating systems shall comply with all applicable Federal Motor Vehicle Safety Standards, including FMVSS 301 as well as SAE test procedures.