Best Answer: it depends on your oven. electric ovens take much longer to heat up than gas ovens. My electric at my old house took 20 to 30 minutes to get to 375 my gas oven in the house im at now takes about 15 to 20 minutes.est Answer: it depends on your oven. electric ovens take much longer to heat up than gas ovens. My electric at my old house took 20 to 30 minutes to get to 375 my gas oven in the house im at now takes about 15 to 20 minutes.