Two years ago I got a hovabator from a friend who couldn't hatch anything in it. I said I would help fix it for her and now I have an almost 100% hatch rate on farm foul. The problem I had was the temperature in the hovabator fluctuating. I researched and found a forum that told me to duct tape a penny to the bottom of the incubator's wafer. I tried that and now my temp. stays at about 98•F-99•F. I recommend that people who have problems with their hovabator's temp. fluctuating, do this to their hovabators. It's a great way to fix it. Also, if possible, use a fan to circulate the air in the incubator. It helps a lot.
NOTE: I've had better hatches with the dry incubation method, you can learn about it here: https://www.backyardchickens.com/a/how-to-incubate-hatch-eggs-using-the-dry-incubation-method
Dry incubation, if tweaked, can work for waterfoul.
Hope this thread helps fix your problems
NOTE: I've had better hatches with the dry incubation method, you can learn about it here: https://www.backyardchickens.com/a/how-to-incubate-hatch-eggs-using-the-dry-incubation-method
Dry incubation, if tweaked, can work for waterfoul.
Hope this thread helps fix your problems

Hens go broody when you don’t want them to… and won’t go broody when you do. 