Poor heater in all the Chevrolet Silverado's i have ever owned
 

Start the truck and let it idle for 30 minutes gets up to 180 degrees if you have the heater fan on it takes an hour to get to 207 degrees. driving in city traffic. I have owned 6 of these trucks 4, 6, or 8 cylinder they all do the same thing, If you do not have the heater on it heats right up.

What year?? I've owned Silverado (or Sierra) trucks going back several generations, not noticed an issue?

Same thing here. I currently own 3 and have owned many over the last 20 years and have never had a heating problem with any of them. Annie's 2004 GMC 2500HD would literally blow you out of the cab it got so hot.

Currently 2024 Silverado 4 cylinder but i have had V6 & V8 I drive 3 miles from home all city driving not over 30 mph

2024 GMC Denali Duramax 3500 DRW and it works like a champ. Plus electric seat. No issues.

When i drive 3 miles from my house going no more than 30mph temp reaches 180 degrees i park and race the engine to 2500 rpm and watch the temp go up to 207 with the heater fan on high speed i let it back to idle speed and watch the temp gauge go back down to 180 every truck i have had did the same thing.

Might want to use "tow/haul" mode, if you have it and keep the trans in 3rd gear for the 3 mile drive and see if it helps. 3 miles with mine in cold weather takes longer too, but there isn't anywhere I can get in 3 miles around here.

At 30 mph, the engine isn’t working hard to make heat, and takes a lot longer to make 4 gallons warm.

I've never had a reason to complain out of all of the GM trucks that I've had.

And by the way it only gets 10 mpg 4 cylinder 2024 (regular cab) 4 wheel drive Silverado all city driving