[dak0415]

I tried putting the probe on the inflow (cold) side with just water in the tun and made the PID autoconfigure.  It kind of worked with just water but once the grist loaded, it takes 3-4 minutes for temperature change at the top of the mash to get to the bottom.

[bo]

That makes sense to me. I think it has to be in the out flow.

[Kit B]

I wonder whether a motorized mixing paddle would change that & help even out the temps, faster.

[bo]

I wonder whether a motorized mixing paddle would change that & help even out the temps, faster.

Absolutely, but good luck doing so in a rectangular cooler or finding something strong enough to move the mash.

[Kit B]

I'll be using a converted keg, so I don't need to worry about that aspect.
That's actually why I'll need a HERMS coil...Little to no insulation on my mash tun.

I have a 1 rpm motor that I'll use to stir the mash (as long as it has enough torque to stir it).
I don't need a paddle, per se...Just stainless steel fingers to circulate the liquid into the grain bed.

[bo]

I'll be using a converted keg, so I don't need to worry about that aspect.
That's actually why I'll need a HERMS coil...Little to no insulation on my mash tun.

I have a 1 rpm motor that I'll use to stir the mash (as long as it has enough torque to stir it).
I don't need a paddle, per se...Just stainless steel fingers to circulate the liquid into the grain bed.

If you get that working, please post some pictures. I think stirring the mash could really help with efficiency.

[dak0415]

I'll be using a converted keg, so I don't need to worry about that aspect.
That's actually why I'll need a HERMS coil...Little to no insulation on my mash tun.

I have a 1 rpm motor that I'll use to stir the mash (as long as it has enough torque to stir it).
I don't need a paddle, per se...Just stainless steel fingers to circulate the liquid into the grain bed.

In my experience (50+ batches with this gear) you don't need to stir it, just recirculate the wort with a false bottom and in a hour you will have crystal clear wort.  I did need to increase my mash ratio to 1.5 qt/lb to keep things flowing well though.  Also a couple of layers of Reflectix around the tun will give you all the insulation you need.  How soon are you going to have this in operation?  Have you already cut the kegs?  I'm working on a new HLT and MLT design that you may be interested in.

[Kit B]

I have the kegs & they are cut.
I have a lot of the plumbing put together & am nearly ready to drill for connections & the element.
I'm working on it very slowly, but I hope to have it operational before the new year.
I'd love to see what you're working on.