DigiQ II Overshooting Set Point


 

Tom Barineau

TVWBB Super Fan
Here is my setup: WSM water pan with 14" clay saucer. 3/4 chimney of charcoal. DigiQ II draft inducer about 1/2 open. Smoker set point at 225 degrees. Top vent wide open. Bottom vents closed. Ring full of charcoal with room left in center for hot charcoal from chimney. Temp. probe dropped thru top vent. Temp. shot past 225 to 235-239. Could I be starting out with too much charcoal in the chimney? Right now I have the top vent open only about 1/4 and temp. is down to 228 and dropping. I wouldn't be worried if I was doing butts or ribs, but I like to keep the WSM at 225 max with brisket and would like to know for the next cook.
 
Hi Tom,

That sounds exactly like the problem I was having with my 1st WSM when I started using the Competitor. I found that my WSM wasn't as "tight" as it should be. In my case, all of the lower vents leaked pretty bad and I ended up taping over them (from the inside) to prevent air from feeding the fire but other culprits can be the seal between the middle and lower section of the WSM and the side door. All need to be fairly tight in order for the Guru to control the pit temp and avoid over shoot issues.

HTH,

Bill
 
That is probably it as I'm using my ET-73 with two food probes and the leads are running under the lid. Right now I've got the top vent about 1/2 open, which goes against the grain for me, but the pit temp. is stable at 225. Reckon I'll run into a problem leaving the vent that way?
 
Originally posted by Tom Barineau:
That is probably it as I'm using my ET-73 with two food probes and the leads are running under the lid. Right now I've got the top vent about 1/2 open, which goes against the grain for me, but the pit temp. is stable at 225. Reckon I'll run into a problem leaving the vent that way?
I thought the same thing initially but being as it's "forced air" and not "natural draft", there's no chance for creosote forming. Keeping the top vent partially closed aids in helping the Guru to maintain the set temperature. You may want to look into the "eyelets" that the Guru folks sell. They are designed to replace the bolts that hold the grate brackets and each eyelet will pass 2 (and sometimes 3) probes.

Bill
 
I looked for those eyelets on the BBQ Guru website when I ordered my DigiQ, but didn't see them. I'll look again and then call them if I have to. Will also take your advice and cover the bottom vents like you did if the eyelets don't help to cure the problem. Thanks for the help. T.
 
Here ya go .. Eyelets

A DigiQ II is on my "to get" list
icon_cool.gif


Take care,

Bill
 
I had just found them. Was probably so excited about ordering the DigiQ II that I overlooked them. I'll get them coming. Thanks, again.
 
WSM water pan with 14" clay saucer.

Don't mean to hi-jack your thread, but I had a question. I'm looking to buy a DigiQ II and thought that I had read with the DigiQ II there was no need to use a heat sink? Is this correct?
 
That's correct but you do have to use something to deflect the radiant heat ~ Balls of foil, wrinkled sheets of foil, or in this case, a clay saucer. I would think that the clay would radiate to some degree, especially on the lower grate, but I'm not sure.

Bill
 
Tom, I just went through the exact same thing. I removed my clay saucer and just had my foiled water bowl by itself with out any water. After fighting it all day long I found out through the BBQ Guru site that it has a ramp mode. If you are using the ramp mode, it will base the pit temp off the internal temp of your meat, once your meat temp gets within 25 degrees of its set point, it will (the blower) not come on. You will experience low temps only to protect the meat from over cooking. All of your vents should be completely close except the top vent and it should only be opened very so slightly. The DigiQ II will do the rest. Now if you choose not to use the ramp mode, your temps will not vary at all once you reach your desired pit temp, and if it does, it will be very little. Just make sure that you haev the top vent barely open say maybe only 1/8th is all it will take. I found that the DigiQII lacks instructions and vital information that is needed to understand how great this unit can and will be.
 
Ed--I don't have it in ramp mode, and whenever I open the top vent back up, the smoker temp. goes 8-10 degrees above what I have the pit temp. set at. I had closed the top vent to about half or maybe a little more and that seemed to help, so will try the eighth or so open. I'm still not so sure that Bill is not right about my WSM not being real tight and is getting air from places other than the DigiQ II.
Thanks for your help.
 
Originally posted by Tom Barineau:
Ed--I don't have it in ramp mode, and whenever I open the top vent back up, the smoker temp. goes 8-10 degrees above what I have the pit temp. set at. I had closed the top vent to about half or maybe a little more and that seemed to help, so will try the eighth or so open. I'm still not so sure that Bill is not right about my WSM not being real tight and is getting air from places other than the DigiQ II.
Thanks for your help.

Yeah Tom as long as the top vent is open too much the temp will go up, and once you put those eyelets in, you will see a noticable difference. That's something that Weber should consider doing on any new models they come up with. They could install eyelets that have a set screw or something simliar in them incase you have no need for them, but at least that would give future buyers of this product the option without having to experience some of these issues. Keep us informed on how you make out on your smoke. GOOD LUCK
 
Tom,

I know of several people that run their probe wires under the lid and don't have overshoot problems so I don't think that the eyelets alone are going to solve your problem. Honestly, I think you have some air leaking in from further down, i.e. the door or the lower vents. With time, the grease should help seal the vents, if that's the problem, but if it's the door, you'll have to work on that a bit.

Good luck with your DigiQ II.
icon_smile.gif


Bill
 
Yes - Diqi II should alarm you when things go over temp. It can't help much when that happens in my view except that it should have stopped any fan intervals at least when the oven temp hit your set point or a little before. It requires that air flow into the fire is closed down and that air intrusion is minimized so it is pretty much controlling that. I have used the dry foiled pan only and haven't found any need for a sink.

AFA the eyelet kits - here's a tip. The stainless steel hex head screws in the kit are pretty small. They can snap off on their way out after you have crushed the eyelet due to the torque applied to crush the eyelet - this can damage the threads. This will keep you from being able to install the second one in the kit. I highly recommend you go to your local hardware store and pick up at least one spare stainless steel hex/allen head screw of the same type before performing your install.
 
The main reason I got the DigiQ II was because we like to boat and wanted to be able to set the WSM up and forget it until we get back 2-3 hours later. So-- I suppose I'll order the eyelets AND seal the bottom vents from the inside. I've read and performed (to the degree that I thought the door sealed) the suggestion about the curvature of the door--bending it ever so slightly. Is there something I can use to seal it and still be able to use it?
 
Tom, I bought a roll of the metal duct tape at Home Depot. Put the door on and shined a light into the WSM. Look at the door from the outside and look for the lit gaps. Take the door off, clean the side of the WSM real well where you saw the gaps. Cut strips of the tape and use it to build up the area on the WSM to close the gaps. I had to use about 4 strips for each vertical side of the door. Each strip got a little shorter as the gap closed. I think I explained that right lol.
I have had to replace the tape about every year, takes maybe 10 minutes.
 

 

Back
Top