hi... so we got snow, which happens here once every few years and is a real big deal; so we were also on 'lockdown' ; i live on kibbutz (like a commune) so the person in charge of cars put the car key locker on lockdown; couldnt go anywhere; also had several power failures and our side doesnt have a generator but nothing major, could have been owrse... temps in our house were about 15 celsius , with heating (primitive heating with radiator and spiral electric heater)...outside was about -2 which for us is like siberia

but the brooder stayed at 39-30 and the bator staid steady since i kept a towel on it...
of the second batch, i have 10 chicks, one has spraddle leg, one has crooked leg but is doing well surprisingly, and several eggs still havent hatched this is like the 24 day...
both wells have water in them and the candy thermometer reads: 37. the past two days ive opened the bator to take out the last chick and to check and dispose of eggs (afraid of eggsplosions)...
meanwhile have four two week old chicks running around the house *(ichh); the house smells like, well, like a hatchery or a chicken coop.. but too cold to put anything outdoors yet...
this incubator seems to work best when u dont mess with it: just put the eggs in and let it go... i dont notice any differenc with humidity affecting the chicks: the ones that hatched, hatched on their own this time round, and the two with defects are probably genetic or egg oriented, not bator problems. the ones that havent hatched are also probably weak or defective chicks, or old or non fertile eggs... waiting til tomorrow and then will dumpt the old eggs and sterilize the whole thing and start to look for different breed eggs...
we actually saw one egg hatched, withthe little wet chick tumble out and start the fluffing process...
good luck.