[Mikendebbie]

The tank heater went out in my (former) 2014 Chevy 3500 SRW at 100,825 miles in early February 2019...825 miles out of warranty (DOH!). Dealer quoted $1100 for replacement. I do not remember if they had the parts or not. I kept driving it for a couple of weeks until DW and I decided to trade it in on a 2019 Chevy DRW. It was not very cold in TX at the time, and besides the "check engine" light being on all the time, I did not notice any difference.

For the 2014 Chevy, I always waited until to add DEF until the warning showed up in the DIC "985 miles to add DEF" or whatever it said - then I would add 2.5 gallons. For my new truck (2019) dealer tech told me I could fill it up with 5 gallons when the message appears. He said you can fill it up to the point where it runs out of the fill port. I have only tried a 5 gallon fill one time so far and it did not run over the fill port.