Brand new to the egg. Fathers day a flop

Definitely sounds like an airflow issue. It could be that the holes in the grate that the lump sits on are blocked. I used a bent wire (coat hanger) to reach in through the bottom vent and poke through the holes to open them up. I had to do this almost every cook until I replaced that grate with one with better airflow. That's at least where I'd look first.

Check your thermometer calibration.  During your high temp burn you may have knocked it out of cal.

Hey brother, this is only a problem because it happened on your day. In the grand scheme of things, this is quite fixable.

Empty the egg of all lump, remove all internal workings. Clean thoroughly.

Reassemble. Add lump and try again. It'll all work out. A year from now, you'll have tons of cooks under your belt and think back to Sunday and just laugh.

I had the same problem on my first pizza cook when I wanted to impress friends.  The egg wouldn't go above 350.  I have plenty of room in my XL for charcoal so after dumping it in I always clear a spot at the front of the grill that leaves at least two of the holes in the charcoal grate unobstructed to air flow.  Now I can get over 1000 degrees any time I want if the airflow is unobstructed and up to about 800 with the platesetter and XL pizza stone in place.  Those aren't usually my target temps - but when I leave the egg alone too long that's where I end up.

On smaller eggs, others have different ways to make sure airflow is unimpeded - like getting an aftermarket grate.

I found if I take my top vent off it really helps to get the temps up there.

@Raymont had my response before I could finish commenting.  The fire ring is about 4" high and the grill sits on that. The fire box is bowl shaped. Fill with lump to the top of the fire box only.

Get a HighQue grate. 

I think @Ozzie_Isaac was probably correct. The higher temp cook messed the dome therm. Thiss assumes that when you cleaned out the previous batch of lump, you did not move the firebox bottom opening from alignment w. the bottom vent.

If you are cooking direct, the dome therm is an approximate indicator of what the food is getting at on the grill. Here is an analogy. You are driving a car with air conditioning. Over all, your body feels quite comfortable. But your left arm, exposed to the sunlight coming thru the driver's side window still gets burnt. Same thing in an Egg direct cook. I've had times when the dome therm would not read higher than 500F. (Turned out that enough lump had burnt to ashes that the air flow was decreased.) But my steaks were still seared. Just took a little longer than when the dome therm reported 800F.

If you remove the fire ring, and put the grill on top of the fire box, anything over glowing lump will be getting 1500F easy, probably more. When I've cooked like that, steaks almost always burst into flame before I can close the dome.

The Egg is an analog instrument. Practice make perfect.

caliking said:

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But I don't think you can overfill the egg with too much charcoal, unlesss you beat it down in the egg to cram in more and in the process block all the grate holes and firebox holes with small pieces of lump and ash.

This happened to me and the thing wouldn't stay lit. My own fault as I wanted to do L&S on the mm while I was at work. Wound up chunking the butt and doing another turbo to meet the deadline. 

We've all been there. Father's Day 2015, did a low and slow all night with 16 lbs pork butt. Pulled the butts, was lazy so I just added some more lump and threw on a tri-tip. Wanted to run it at 350. Pulled the daisy and opened the lower vent all the way open. Got it up to 330 and just cooked it a little slower. Later in the day after everything cooled off, I started preps for the next time. LOTS of ash in the lump so I verified it was an airflow problem due to laziness. Oh well, have a glass of wine and get ready for the next cook.