Check the heating elements.They are the left, right, top, and bottom walls of the chamber.If or more of them is cool, while the others are warm, they will need to be replaced.As there are multiple variations, you will want to check the website and/or call HMA Lab Supply to ensure you order the correct part.Please verify your model and SN as outlined in the “General Information” section prior to ordering
If the left and the right heating elements are not heating, you will want to ensure your furnace is not in the low-power configuration.This is an older configuration that was designed for 20A use and disables the left and right elements.To check the configuration, unplug the furnace from AC power, open the back panel of the furnace and check the lower left-hand corner.There should be a wire joining the two connectors there.If it is either not present or connected to itself, then the furnace is in the low-power configuration.
