I have Hotpoint range that I bought last year (it was one of the highest rated 30" ranges by Consumer Reports). I use it with a Hearthkit for bread, and I begin heating the oven about 1.5 hours before I put in the first load of bread (takes a while for the hearthkit to really warm up). -- A lot of heat escapes through the vent at the top of the range. I assume it's a safety feature, but this seems odd in that I assume the oven should be trapping as much heat as possible and relying on the thermostat to regulate temperature. -- Do older ranges hold in more heat? Is it OK for me to at least partly block the vent, perhaps with a wet towel, or is that too dangerous?