I'm running a Honeywell "The Round" thermostat on my Keystoker. I've been very pleased so far. It has an adjustable "Cycles per Hour" rate between 1CPH (for steam/vapor heat) up to 9CPH (for electric forced air). I'm using the 3CPH setting and it seems to hold a very stable temperature. It will overshoot badly if you crank up the room temp way over the current set point (5 deg. or more), but otherwise will only overshoot by a few degrees. It's in a fairly small basement room that is well insulated, so it's not much for a 90K BTU stove to really pour out the heat once it gets cranking good.