Ok now I get the picture. Can you say schmoke and a pancake? That sounds like something I would do in the future for sure. I have the pump, and the same temp control as you. So what setup are you running to heat the HLT besides the controller ( I am guessing electric?) ? Also do you just strike at whatever temp you would normally and then fine tune?
So what is the electrical part that is at the top of your HLT?
I have an electric water heater element secured into the bottom of the HLT. I also have a mixer, so that there are not cold spots around the HERMS coil, the water needs to be mixed thoroughly during this process.
I heat my water in my HLT (9.5 gal) to strike temp +10F... this allows me to pump the water over into my MLT and preheat it. When my MLT thermometer reads my strike temp, I mash in. Say 172F, cooled to 162F in my MLT, to rest at 152F after mash in.
So now I have about 6 gallons of 172F water left in my HLT that I need to get down to 155F so that I can recirculate... problem? No. See I need more than 6 gallons to sparge with, so I created a program that will calculate result of adding 1.5 gallons of water (to meet my sparge requirement) to the HLT to cool it to 155F precisely. The volumes can be swapped around, say 9 gallons to start, 5.5 left, adding 2.0 to cool it down to recirc temp...etc. This is all computer calculated.
So I add my 1.5 gallons at 68F to the HLT through a small hole in the lid where my thermowell is inserted with a stopper, my HLT cools to 155F, I open the valves and it runs like that for an hour. (155F because there is a 3F differential in my system between the HLT temp and the desired MLT temp)
The wort is crystal clear within 20 minutes, temps are precise... it is very wasy to brew this way.
Clear as mud? The electrical part at the top of the HLT is the mixer motor probaby, and my A419 thermowell is inserted through the center of the lid.
Here is a breakdown of a typical mash, water temps and volumes.
9.5 gallons in the HLT heated to 172F
3 gallons transferred to MLT at 172F
3 gallons in MLT cools to 162F (mash in)
Add 1.5 gallons of 68F water to the MLT to cool the water to 155F
Start recirc...
After 60 minutes, turn A419 up to 175F
Mash heats to 168F
After 20 mins, begin to sparge with 175F water and collect runnings
Collect 7.5 gallons, boil 90 mins, 5.4 gallons post boil