Thermometers way off

[jac7676]

I have 2 digital thermometers I use to measure pit temp. One is a BBQ Guru that is also regulating the temp of my BGE. The other is a cheaper Maverick ET-732 that I use so I can relax inside and still have some idea of what is going on outside. They usually differ a bit on temperature readings. However, tonight I am smoking a whole packer brisket and for the first time ever my two thermometers were reading within a couple degrees of each other for about 5 hours. And then suddenly the Maverick climbs from 225 to 300 (and still climbing) and the BBQ Guru is still sitting at 225. I'm not sure what to make of this. Obviously, it is a big deal and I need to get it figured out.

[boftx]

I have had Maverick probes go bad and read about 30 - 50 degrees low because of bad cables. My gut reaction would be to say trust the Guru if it has a steady temp line and replace your probe(s) on the Maverick. I have an ET732 and wouldn't trade it for anything, but I always, ALWAYS keep two spare probes on hand just in case something like that happens.

[Breadhead]

+1^ on what boftx said. By looking you can tell your cooker didn't make that big of a swing temp wise.

[CeramicChef]

Before I'd go buying probes, check them all against boiling water. Don't let the probes touch the bottom of the pan or you'll be replacing more than one probe. I'd suspect the Maverick, but just to make certain ...

[boftx]

jac7676 Be sure to test each probe in each jack on the Maverick to be sure you can tell if it is a probe or the unit.