Assisting RIMS with propane.

Im working on a half electric BIAB RIMS system. I plan to use my propane burner to get my keggle up to dough-in temp, proceed to dough in, then power up my home built RIMS tube with PID to maintain the mash temp in the keggle. After I begin the mash, the propane will remain off until the mash is over. I will use propane after the mash for the boil as I dont have enough power available to power the elements required for a boil. The keggle drops temperature quickly especially with 5 gallon batches because of all the surface area, not to mention the weather outside.

Will doing this confuse my PID? Should I let the PID handle getting the temp up to mash-in? From what I understand these things calculate how long it takes for the temp to reach its target, and continually learns from it. If I start the water out at a high temp before kicking on the PID, will it think it needs to work less hard to maintain the temp, and having my mash temp suffer as a result?

Thanks for the help.

I do basically the same thing you are describing. I heat my strike water with propane, mash in, and then turn on the pump and rims element. It takes about 5-10 min. to get a stable temp. for the rest of the mash.

Excellent good to know, thanks a lot.

I do this too but I turn the PID on at the start and set it to zero output on manual mode. I keep the water circulating with the pump to monitor the temp and I set my high temp alarm to 5 degrees below my mash in temp. I can then ignore it and get stuff organized until I hear the alarm. After mash-in, I turn the PID back to auto mode and let it do its thing. For a second rest or mash-out, I go back to zero on manual mode and fire up the burner and set the alarm again. On manual mode, my PID is not "learning" anything and it performs appropriately at maintaining temp in auto-mode.