My orginal LL Hyfire only had the Rheostat controls, speed up or slow down the feed rate and/or blowers. Going to basement to adjust wasn't gonna happen. LOL. I ordered the CoalTrol 8 years ago to accurately control my stove.
The CoalTrol takes all the guesswork out of controlling your Stoker Stove. it has a lot of built in features to control the temperature, blowers, feed rate, etc.. all based on the setpoints and room temp (Along with a lot of algorithms these guys program into it to automatically adjust stuff).
Everything is controlled by the thermostat mounted upstairs in the living area. You can manually run the blowers, change feed rates, etc... once you get it Dialed-in, a little tweaking of the Min. feed (to maintain idle fire) and MAX feed, so you're not pushing hot coals off the grates. It maintains a constant temperature very well.!! it automatically adjusts feed rates based on the temperature setpoints and room temps and will adjust accordingly.