Temp fluctuation

[1southpaw]

I built an incubator out of an old dorm size refridgerator and used a hot water heater thermostat. I can't seem to figure out how to get the temperature to hold steady, it fluctuates roughly 10 degrees. I have an old computer fan that kicks on when the thermostat kicks on. Does anybody have any ideas? I haven't put any eggs in yet and kinda afraid to with the fluctuation.

 

[Mahonri]

First off, Welcome to BYC!

The fan needs to go continuously, not just when the thermostat kicks on.

 

[1southpaw]

Thanks for the welcoming and the help. I will give it a try and go from there.