Mueller climatrol furnace fan switch W-145-150
This old furnace heats the house just fine, but the fan stays on nearly all the time. Is the problem likely to be the fan switch or limit switch? I can't find a parts diagram of the furnace. The switch I'm looking at has L4029C 1206 1 CG3 printed on one side, an adjustment on the other side that says limit, and is connected to two wires that come from the gas control unit. The questions are whether that switch is the problem and whether there is a way to test for the problem.