Knipfing and KASI president Roger Filion offer other maintenance tips for KASI infrared units. "Routinely check the lines and connectors on the LP gas system and replace o-rings on POL fittings once a year," Knipfing says. "Blowers that pressurize the heating system and mix the fuel and air are relatively maintenance free, too, thanks in part to operating a 12-volt system that puts less wear and tear on the blower's motor."
"The armature life on these motors is two years, and brushes last a year or longer," Filion says. "They can easily and inexpensively be replaced at the end of the season."
Ray-Tech Infrared, Charlestown, NH, offers a line of six infrared asphalt heaters with a converter heating system. Engineering manager John Strich says Ray-Tech-designed pavement heater converters on its Total Maintenance Vehicle which feature a 2-, 4-, or 6-ton capacity reclaimer/storage unit and a 48-sq.-ft. infrared pavement heater, and all other Ray-Tech models, employ a 24-volt Ray-Tech designed DC brushless motor system, eliminating replacement of brushes and armatures. The 24-volt DC system is supplied by a separate alternator on the truck, or by a battery system. Under heavy use, the Ray-Tech's converters normally last up to eight years and the grids two years. Therefore, maintenance on the converters and blower motors, for the first two years, is virtually non-existent.
Strich says minimum maintenance consists of keeping the stainless steel chamber clean and making sure that the surface louvers do not get crushed or blocked, thereby restricting proper air flow. The grids are made of very soft material and should not be bumped, flattened, or pushed out of shape. If this happens, or if holes are visible, remove the grids and straighten or replace them, as needed. The reflectors should be periodically painted with high-temperature aluminum paint, and the heaters should be visually inspected at least twice daily to ensure that all burners are properly lit.
Normal maintenance also includes daily examination of the propane supply system for leaks, and batteries should be checked for acid levels weekly and hydrometer tested monthly. Where the battery system is charged by a battery charger unit, recharging nightly is required. When the unit is not in use, the batteries should be charged at least once a month.