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. Thermostat wiring color code decoded - YouTube Jul 14, 2015Thermostat Wiring to a Furnace and AC Unit! Color Code, How it Works, Diagram! - Duration: 5:39. AC Service Tech LLC Thermostat Wiring & Replacement- Where can I find a SCHEMATIC DIAGRAM to a Climatrol Gas May 05, 2013I am repairing the (burned) wires in my CLIMATROL Gas Fired Up-flow Furnace. I need a schematic Diagram to this 174-0 Series unit. Where can I find such a document to this furnace in addition to the customer owners manual?