Emerick B New Orleans , LA December 01, 2016 Appliance: Tappan Tappan/Range TGF317DWD Tappan Range Tgf317dwd: The oven temp was swinging wildly making baking impossible. How to replace Oven Thermostat. Ordered a new thermostat, installed it in about 15 minutes, and now the temperature stays within about 10-15 degrees of setting. 4 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes