Is your transit bus fleet ready to cope with the winter?

Although we are still enjoying the comfortable warmth of the late summer season, now is the best time to start preventive maintenance on your auxiliary fuel-fired coolant heater for maximum comfort and reliability throughout the winter months.

To begin, inspect auxiliary heaters, coolant pumps and related systems for proper functioning and possibly, a tune-up or basic preventive maintenance before the onset of winter.

A good visual inspection of the heater’s mounting hardware, coolant lines, fuel lines and electrical wiring done now will give you plenty of time to make any necessary adjustments and repairs before the cold weather settles in. Also, be sure to replace any fuel filters, or air filters if equipped at least once per year. Most large capacity heaters will require some internal maintenance such as cleaning of combustion tubes and the inside surface of the heat exchanger of accumulated carbon deposits. Some heaters will also require a new replacement fuel atomizing nozzle annually.

Make sure to check the area around the heater for accumulated debris. Also take a good look at the exhaust tubing for damage or blockage. If your heater is equipped with air intake tubing, you’ll want to inspect it as well. Take note of any uncovered issues and set a course of action for repair.

Keep those vehicle batteries in top condition. Your heater will not perform at its optimum level if it cannot get the power it needs. Clean the battery terminals and surfaces of contamination and keep connections protected with an application of a dielectric compound to ward off corrosion.

After completing all visual inspections and making needed repairs, run the auxiliary heater to further diagnose its present operating condition. Various heater manufacturers offer diagnostic tools to aid in the detection of problems within the heater.

Auxiliary heaters should be periodically run throughout the year. It is recommended that the heaters be run for a minimum of 20 minutes at least once monthly during the off-season. This will keep moving parts lubricated and fresh fuel in the fuel system.

Many auxiliary heater manufacturers support their products with technical manuals and related documentation. Most are available at their respective Web sites.

If at any time the instructions are unclear or you feel uncomfortable about the procedures suggested in this article, or have questions about the documentation for the auxiliary heater, or if you have questions about the equipment, contact the manufacturer’s authorized trained specialists for professional advice and assistance.

Ron Cowell provides technical customer service for Spheros North America Inc., a developer and manufacturer of heating systems, air conditioners and roof hatches.