PID autotune question

I have a RIMS and bought a new water heater element with a higher wattage than the existing one. I was gonna install and run the autotune function. Do you think recirculating water instead of wort will make much of a difference?

I think as long as you set the water flowrate to approximately what your recirc rate will be during a mash, it should work just fine.

Make sure you start the auto-tune after you’ve got the flowrate adjusted and the water around mash temps.

+1 I BIAB and continuously recirculate with a direct fired kettle. Using water or wort when auto tuning is a mute issue, in my experience. I have helped others automate their rigs. On the other hand; flow rate and heat output (BTU) WILL have an affect. I use my PID w/RTD to heat the water to strike temp and then to maintain mash temp. I do try to set the burner to the same BTU setting each time, but I don’t get too anal over it. The PID does correct/adjust a little. But it has not been a problem for me. YMMV

When you say  “around mash temp” can you be more specific? I was thinking of preheating the water to around 110f and going from there.