Used a plastic cooler with 40 watt candelabra bulb placed 4" off the bottom on the short side beneath the handles. WHT is attached via 16" wires. 4 inch desk fan resting on the floor of cooler on opposite end of 40 watt bulb, blowing at the bulb. 10 qt-sized mason jars line up on the right and the left leaving a channel directly from the fan to the bulb.(5 on right and 5 on left) Wire mesh is supported on top. THis is where I place the thermometers and eventually the eggs... THe WHT can be moved to any location. I have been trying several locations; the best was 97 degrees and being a perfectionist, I moved the WHT and increased the setting on the WHT. Now the bulb doesn't come on, except for a flicker once. SO the bulb is still good and the wiring is correct. I placed it close to the bulb and got a flicker, nothing more. Where do I need to place this WHT to make it work? What temp to set the WHT?