Ok, WHERE are those probes? Inside the enclosure or out? The best way I found to do it with my Johnson and Ranco is to use foil tape to tape the STAT probe under the UTH near the center (or place it between the glass and heat source if you can do that) and place the thermometer probe under the substrate under the warm side hide using the hide to hold down the wire. Then, you adjust the stat until you get the readings you want off your acurite. Expect a difference between readings based on substrate and air. I use my temp gun to double check the readings from the acurite and there's always a difference of at least 3 degrees between the two numbers.