Refrigerator is about 8 yrs. Old and is losing cooling on the bottom and heavy frost buildup in the freezer part. We recently discovered that the icemaker line was hooked up to hot water. Can the frig be repaired or is it time to get a new one?

You definitely should keep that refrigerator and replace the defrost system and clean it inside and out, especially the coils, and you will have a new unit better that the new ones that use R-134a that use 50% more electricity and break down more often. A new defrost system is about $50. $12 for a defrost timer, $20-30 for the heater, and $5.00 for defrost thermostat (also called defrost terminator). All the parts are easy to install, too. Hook the ice maker up to the cold water line.