When you first introduce the eggs into the incubator, it will be several hours before the temperature returns to its set value because the entire mass of the eggs needs to be warmed. Your incubator was probably designed to operate in a room at or near typical room temperature. If you locate your incubator in an area that is too cold it may not be able to maintain correct incubation temperature. It will get too hot possibly killing some or all of the developing embryos. Monitor temperature closely, especially if the temperature of your house is not closely regulated.
Humidity is maintained throughout incubation by putting water in the bottom of the incubator.
If you are getting a large amount of condensation on the windows, you may reduce the amount of water used. About three days before hatching, the humidity should be increased by introducing a wet sponge or rags into the incubator. This makes it easier for the chicks to peck their way out of their shells. A broody hen does this instinctively. You, acting as mother hen, must turn the eggs yourself.