I have Herpstat that reads error four messages (supposedly because of a probe dysfunction) even after I JUST replaced the probe.

I also have a Ranco (brought in last week) to replace the Herpstat, that reads 83 degrees, that it should be at 91 with a 1 degree differential. My thermometers also read 83 degrees. It appears to be giving my heat pads (I tried this with both zoomed and the laminated flexwatt pads from the Bean Farm) full power, yet they are NOT warming up.

This Ranco worked fine until last night when temps started falling. This morning it was the same.

I am soooooo frustrated and upset. This is my THIRD thermostat that has failed!!!

I have called Ranco and the customer service guy wasn't in. ANy help or ideas would really be appreciated as this is putting my life on hold right now, and I really need to start getting to classes today.