My Hova 1590 is having trouble holding temps. I may be able to baby it through this hatch. It is now covered with a blanket, and the temp is getting close to 99.5. I contacted the company, and they no longer make this model. According to the person helping me over the phone, it would cost $100+ to buy a new heating unit for it (includes shipping). If I have to spend that, I will buy an entire new incubator. Any suggestions on replacement parts from other bators that might work for this one--at a more reasonable cost?