Incubator temperature issue?

[eulogos]

I have had some wonderful successes and some terrible failures this year. Successes this year mostly due to the broodies. I did hatch 8 in the incubator early from when a hen quit sitting during a spring cold snap. Anyway, this is about my horrible failure. At the same time as I set my broodies, I started some in the incubator so I would have chicks to give them if their eggs did not hatch. Well, I gave 5 broodies 6 eggs each and got 24 chicks from them. But of two dozen in the incubator, only one hatched and that one died and it was not pretty. From candling, all the eggs developed quite far, but after waiting 5 days extra, they were dead. I am wondering-even with a thermostat, can the incubator get too hot? It was on a table by a window. Could the sun shining in have made it too hot and killed them? I put two thermometers in there at the end but one said too hot and the other said too cold! Can anyone recommend an accurate thermometer?

 

[paneubert]

What is the range of your thermometers? Any thermometer can be accurate if you are able to calibrate it (basically know how far off from accurate it is) with either ice water or boiling water.