Those digital thermometers are not very reliable. I know, I have used many of them. Maybe use a couple different ones in there and see what they say.
If you ever get a chance to get a new one, I recommend this one..... It is made specifically for incubators, and is accurate to within one tenth of a degree.
Read about it here.
If you ever get a chance to get a new one, I recommend this one..... It is made specifically for incubators, and is accurate to within one tenth of a degree.
Read about it here.