I’m not sure where the correct place is to post this, but it seems like I read more about probes in this room than the boiler section. I have a Switzer wood fired boiler. It’s what is called a 3 pass system, in that the flue gasses pass through the surrounding water jacket three times before they exit the flue. (See attached diagram from the Switzer website.) I currently have some UbiBot probes in the flue and on the water line to monitor temps, but I’ve been dreaming of putting a couple of more flue probes in because I’m curious what the temp drop is after each pass. (Curiousity killed the cat, I know…) In your opinion, what would be the best probes for this? They need to be WiFi preferably reporting to an app that outputs some sort of chart. The one after the first pass and second pass wouldn’t be a big deal, I don’t think, as their are boxes outside the boiler envelope that I could access quite easy. I know Auber makes a box that you can plug a K type probe in that is good up to 1,650F, but I think it has only one input, and I’d like at least three. Also, the one I see that perhaps isn’t possible is the one right before the first pass, as it would be in direct flame contact, and I’d also need a way to run it to the back of a 24” long firebox. I’d settle with skipping that one if I could do the other three. I’ll attach a few pictures.