I have been using a RIMS system with a PID, RTD sensor and a ssr for years. I have had good results. However, I want to convert the rest of my system to electric. Those 3 items from Auberins are approximately $100. Water and wort temperatures are easy to control with a Potentiometer for a fraction of the price. Once the wort comes to a boil in the bk,Turn Potentiometer up or down to control the boil. In the hlt, when I use propane I would shut the burner off and sparge after my temperature was reached. I have had no problems in the past controlling my temperatures with propane burners. As of P-J's question, The manufacture said that it is a ssvr. I would never leave my system while it was running and my hlt has a thermometer installed in it. As of Bobby M question, I'm not rich nor poor. I enjoy building things and all gain brewing. I think tickling a Potentiometer knob would be no different than tickling a propane knob? Hlt temps and bk temps are not rocket science. RIMS temperatures need to be a little more precise. As of the price difference, I would save approximately $85 going with the Potentiometer and ssvr rather than the pid, rtd and ssr. I can brew a lot of beer with $85. P-J thank you for your response. I'm going to try a Potentiometer set up with your diagram. Also, Bobby M thank you for input.