I just bought one on Saturday from Lowes. I was having the exact same issues. Brought it home, assembled it, primed the auger per directions. It fired up but wouldn't get hot, just warm. I thought maybe I didn't prime the auger enough so I forced fed it some more pellets by holding the prime button down a few more times throughout the heating up process. After a very, very, long time it finally got up to 350 and I left it there for about 45-60 minutes.
The next morning I tried again as I was planning on smoking a chicken on it for dinner. I had same issue on start-up. I messed around with it a couple of times an had to force feed it pellets again to get it up to temp. It would start up, reach about 130 degrees and then just fall on its face. It stayed around 130 for about an hour! Finally forced it up to temp by pressing the prime button a few times again and I did cook my chicken. Once it's was up to temp it would hold. Scratched my head a bit and slept on it. Decided today I would try once more to let it do the start-up per the manual and if it didn't work I would try one more thing. Well it didn't work. Same deal, it fired up, started warming up slowly and once it reached about 130 it just hung up there and then started losing temp dropping back to 119 before I gave up on that and powered it down. The auger was clear of debris and filled up with pellets and things seemed proper and functioning okay but it just seemed it would not drop pellets often enough to get the fire going strong enough to reach temp. On one start-up I even "hand primed" it by putting a handful of pellets directly in the fire pot before I powered it up. Didn't seem to matter much.
Only had one idea left up my sleeve and that was to fire it up per the manual but once the smoke cleared, let it run for about a minute with the door open and get to a roaring fire then close door and turn it up to HIGH. After letting it cool from the initial try this morning, unplugging it and plugging it back in that is exactly what I did. I fired it up and once the fire was roaring for about a minute I turned it up to HIGH and left it there until it hit 300. It was about 36 degree ambient temp and it hit 300 in about 30 minutes. Once it got it to temp it maintained well. In fact I was very impressed with how well it maintained temp even in some pretty windy conditions. I let it run for a few hours adjusting the temp down from 300, 250, 200, and finally 175. At each setting it held it's temp well. I powered it down, let it cool and did it once more. Same drill, fire up, run until fire gets a roar, then close door and turn up to HIGH. It worked again. It was about 30 mins from power on to 300 degrees in an ambient temp of about 50 or 55.
I couldn't care less if it goes above 300 frankly as I want to smoke not bake. I do wish it had a 275 setting though. That's where I like to do chicken but I can live with 250 as long as it will hold the temp. So, for those of you having issues with these things getting up to temp in the typical start-up mode you might try this procedure yourself. It seems to be working for me. When it's set to high the auger runs a lot which is what it needs to get a strong fire going in order to get hot. If I have any other issues later I'll post back here. Jury is still out on this one as far as I'm concerned. Yesterday I was ready to return it to Lowe's and had already started researching others but I'll give it a chance at this point. Hope this helps someone else. Seems the control panels on these things needs the firmware update Pit Boss is promising. A download through the app would be great but it doesn't sound like that is going to happen. They need to come up with a solution though and they also need to respond to posts on their website. COVID is not a legit excuse when they can respond VIA a laptop from just about anywhere.
