That might work. I'm not familiar with the ezboil but the description of the ezboil says it can be used for *some* mash systems, I assume it does not have PID logic. It sounds like it uses more of a thermostat logic? If that's the case that makes it good for putting the probe within the RIMS tube where temperature changes happen quickly, but *probably* not good for placing inside the mash tun where temperatures changes relatively slowly. A properly tuned PID unit might be better for what you propose... one way to find out though.
It seems to me that if your going to go to the trouble of two controllers that it better by all hands off. At this point you might as well just do as bobby recommended and just have one controller with a probe in the RIMS tube and know from previous experience what the to offset the controller to get the right temp in the mash.
Thanks for the reply.
My concern isn't the offset, it is unnecessary off cycling of the element, delaying achieving target temp.
The ezboil has decent logic and autotype, as good as their other units afaik.
I have a spare inkbird STC style controller, so it no more trouble or cost than the wire hanging from it and a second probe, though I'm not sure if they accept the rtd pt100 probes I'm wanting to use.
Not trying to play devil's advocate here. I have a tendency, like others here, to over engineer at times. But, I only want to build this once.
A bit more about my situation:
I do 12g partygyle batches.
Usually a big beer, followed by a 5-6% brew.
I use a 30g Coleman extreme as my mash tun.
Now, that's basically results a 1bbl mash size.
220 is not an economical solution for me. So, with the limited BTU of a 2k/110 element, the desire to not have the element cycle off, I believe, is a concern.(run on much?) I don't want to wait 15-25+ minutes for a 15° ramp due to the limited heating capacity to volume ratio.
I have experimented with full bore recirculation with my setup and haven't had any issues/cavitation. I don't think scorching would be an issue with enough flow.
Now, if I'm over thinking this, please tell me so. Without having it all together, I wont know how much off cycling will occur. But, like I said, I only want to build once.