I build custom draw off units identical to a marcland for a 1/3 the price. A basic model is accurate to .2 of a degree and is standard with a 1' stainless solenoid valve and thermocoupler/probe and a high temp alarm at a low price of $350. i can also inter grade hot temp shut down for oil, stack temp for wood, low sap level alerts. units can be either 110v or 12 volt i also make and sell temperature controlled vacuum pump start and stop switches for 65$ shoot me a email and see what i can do for you