Recommendations for Dual-Stage Controller?

I think you got a lemon . . . you can swap out the probe relatively cheaply, that'd be my first choice followed closely by swapping out the entire unit. My 308 updates "actual" temp continuously, never really a lag. IMO, the Inkbird ITC-1000 is equally good for half the price . . . it does require you to wire it (must add a receptacle), and I mounted it in the cardboard box it shipped in. My guess is circuitry is identical to 308/310, at least the programming and responses are the same.

If dead set against the Bird del Ink, my Rancos have never failed me. They are available as single or dual stage and I believe you have to wire them (at least I wired mine). They have a tiny gray-scale temp window that was state-of-the-art when Clinton was prez. The one running my keezer hasn't been touched in years. Last time I looked they still cost more than their Chinese cousins.

 

I've also been very happy with the inkbird, but your post makes me wonder. After a few uses, I noticed sometimes my Inkbird seemed "stuck" - if I went to set the temp again and then just exited, the temp would start moving again. It never crossed my mind it could be as long as a half hour though and when I tested it like this it was always withing a few tenths of a degree, nothing major. Gonna take another look though.

 

I have the ITC-308 and it updates temp in real time and have not had any issues with it at all. Maybe you happened to get a defective item.

 

When I open my ferm fridge I notice the Ink's "actual" temp display start rising within seconds. It's shown in "tenths" . . . and the digits roll up pretty quickly. As soon as I shut the door I notice the displayed temperature start creeping back down. If I touch or breathe on the probe it will jump ~5 degrees within seconds. Good news is probe is plug-n-play and isn't too expensive . . . bad news, if problem is circuitry you now have two probes to a defective unit.

 

If I had to take a guess I would say its the circuitry not updating the temp from the probe. Seems like the probe would be a either it works or doesn't type thing, but I could be way off here its just an estimate guess lol