Frost has been building up on my freezer wall. I unplugged my freezer and let it melt for 2 to 3 hours. I then took the back inside cover off in the freezer. There was a little bit of frost still on the coils. I plug my refrigerator back on and put manually turned the defrost timer into defrost mode. I notice the defrost heater came on. It was glowing red for about 10 minutes and melted the rest of the frost up. Is it normal for it to glow red for only 10 minutes and not the whole defrost cycle?

Also, I turned put the cover back on and let the refrigerator run. After 3 hours I could feel that there was frost on the evaporator coils again by pressing against the back cover. Is this normal for the frost to build up again in three hours after it looked defrosted? Putting it in defrost mode again doesn't get rid of the frost completely. It is still cooling well, but I'm worried the frost will build up again to the point where it won't cool. I thought the problem was the defrost timer. Is it normal for there to be frost on the coils so soon? Thanks for your help.

Thanks. I noticed that after the frost builds up to a certain level, the defrost heater is not able to melt it completely. If I completely turn it off and let the frost melt for a couple of hours, and then turn the refrigerator on, I can tell frost gets on the coils. I then put it into defrost mode and it melts everything. This all works 1 hours after starting it. If I let it now run for another 2 or 3 hours and new frost forms on the coil, the defroster isn't able to completely melt it. Is this normal? It isn't on the back wall yet, but I can feel by pressing on the wall that is on the coils.