Very slow temp ramp up.

Was the turkey close to the probe?

Had an empty foil pan on the shelf with the probe to catch drippings for gravy. 2nd from the bottom I think. Turkey was one or two shelves up.

Did you have a breeze blowing into the exhaust?

Nope, no breeze, sitting almost in a corner on the deck. against a wall to the family room and about 6ft away from the sliding door for the kitchen. Gonna give it another go, got a rump roast in right now. Gonna bring it up to 325 again and see what happens.

Three things from my perspective,

1) temp probe wires may be loose or pinched.
Check them out
2) you may have a ground problem. make sure you have a good ground on your outlet and cord and avoid a GFCI if possible
3) old pellets can burn but produce much less heat, (especially if you have them mixed with new ones and the auger is getting groups of bad pellets. This is a remote problem though.

I would definitely look at the probe wires before calling service. also fire it up from a different circuit.

I have an outlet here at the house that will make my FEC 100 jump all over the place.

Today, it seemed just fine, except for the erratic temp readouts. Took about 25 minutes to get up to 325 from 210. The erratic readouts only happened when I was kicking up the temp not during the initial startup.

Another thing I noticed the last few times, on the initial warm up, it seems to feed quite a few pellets. The firepot closer to the hopper has a good flame going, but the side closer to the exhaust has an accumulation of pellets that aren't burning. I've opened the hopper cover for a while to stop them from feeding once I get a good fire in the entire pot, I've closed the hopper and all was fine.

Firepot cleaned out before the cook. Using a fairly fresh bag of Lumberjack 100% pecan, plugged into a GFCI outlet that doesn't work. Need to replace it one of these days.

My previous 45 to 60 minute times to achieve a large temp bump-up (224 to 350) when finishing off a prime rib per Smokin's method were resolved after talking with Cookshack and their recommendation to switch to Cookshack's pellets. As they say and I now believe, there are some pellets out there that just don't perform very well. If I use their pellets I can usually now achieve a 125* temp bump-up in about 20 minutes or so. Talk to Cookshack about pellets to get their opinion on Lumberjack brand.

I think my FEC100 also went thru some strange temp displays when taking so long to ramp up the temp. It does not do it now - can't say why not any longer, but may be it just does not like using those "bad" pellets. Yes Cooshack's pellets are a bit spendy when freight charges are added, but for me their performance is worth it. And yes I do go thru lots of bags of pellets now that I bought the PG500. I just buy in large quantities (1000#) which brings the per pound cost down a bit, or at least it seems that way.