You haven't set your eggs, and you are trying to hit 65-70% humidity? Please don't.
Your basement should have some relative humidity to work with. Try setting the eggs without extra water, without the humidifier. Hold off on setting eggs until you again have a stable temperature in the incubator. If your basement is below 65, you may need that space heater.
Too much humidity through incubation is not good. 40% is a safe starting number, and it shouldn't take heroic measures to achieve.
I believe its being used as a hatcher, so the eggs going in will be for lockdown, not a new setting.