Daniel T Hutchinson , KS June 02, 2015 Appliance: Estate Refrigerator TT18HPXLQ01 Estate Refrigerator Tt18hpxlq01: Refrigerator would not maintain a steady temperature. How to replace Refrigerator Temperature Control Thermostat. Replaced the thermostat. The website was very helpful in helping me diagnose the problem. My refrigerator maintains a perfect 35 to 38 degrees now thanks to AppliancePartsPros.com. I was also happy with their pricing. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes