Oooh I hate that! That was why my still air got demoted. Thing spiked all over the place.
Luckily it is forced air...but it's old. What incubator are you currently relying on?
We also have the hova bator. I think I was able to correct the problem I was having with ours fluctuating. The thermometer that came with it is not accurate. I put a GOOD thermometer in and the one that came with it is about 6-8 degrees off. No wonder my chicks were dying. When it fluctuated degrees I had 2 problems. One was the I accuracy of the thermometer and the other was the condition of the room I had them in. We heat with a wood stove and let it go out over night. I have had so many chicks ready to hatch and died over night. The incubator wasn't able to sustain the difference of the temperature in the room. Now we have it in a room where the temperature does not fluctuate as drastically, although it is on the chilly side. The bator is now stable and only 7 of the 30 or so eggs are died. When the temperature dropped, my thermometer read 97 but it was really way below that which is why they didn't make it. I expect much better results now. Blaw! Fluctuating temps are frustrating!
Thanks for the tip! I do have a new accurate thermometer so incorrect readings shouldn't be an issue. Room temperature should remain stable +/-2degrees or so.
I just hope the temp fluctuation hasn't caused any deaths...Only time will tell.