Help crazy thermostat

My problem is that I set my thermostat to 95.Came back and thermostat said 94.I looked at my thermometer and it said 102.6
I set it to 92 hoping that would work better and am now at 76.8.It comes on for about 10-20 sec then shuts off and comes on in about 2-4 min.Is the metal probe retaining heat?.Also the thermometer is in the bottom of the of the 31qt tub with about 1/2 inch of aspen on top.The Thermostat is a Johnson A419 and there is a metal piece on the probes end.Also it is 8 watt 4" flexwatt.

Place the thermostat probe directly on the flexwatt, not in the enclosure. Get that temp to read 92-94 with a thermometer/tempgun. The setting on the thermostat can vary several degrees from what is desired to get the actual desired temp.

My thermometer probe is on the bottom of my enclosure.The thermostat probe is taped directly to the Flexwatt.I really cant figure it out??

Are you sure the probe is completely secured on the flexwatt?

yes all the way on the flexwatt.

Is there a gap under the tank for some air to get through? This is pretty puzzling!

Its a 31 qt tub that is on somthing like a rack.The probe is about 1 inch to the right of the tub.thermometer probe is in the tub under the substrate right now thermostat is set point is at 90 and the tub temp is 96 in bottom although it is shut off ATM.I guess i will have to play with it but i really dont have the time :(

Did you give it sometime to stabalize?

What kind of probe thermometer are you using to measure the hot side?

Nothing to special a corallife digital thermometer.Has worked great for me in the past...

I'd have to say again you might have just got a bad tstat. I guess this is why people say get the whole setup done and checked out before animals go in it, I hope this is what you are doing now. As I suggested in the other thread, if the one you have now is on/off you might as well just toss a cheapo 500R tstat on there for the time being until you have the funds for a herpstat and return what you have now. If you have the probes set up properly and it isn't user error then unfortunetely that only leaves a defective unit...