Reply to "Thermostat"

...Also; as Jack D. has mentioned, check your pressure tank cap for leaking!!! A cooling system that can not hold it's Pressure WILL boil over. That's just the laws of physics. AND don't forget a 50/50 mixture of water to "Anti-Boil"! This Raises the temperature point at which the Coolant CAN boil. I use distilled/purified water,(YES, you can buy it at the grocery store), and 'PRESTONE' Anti-Freeze/Boil. So Check that cap, and be sure to bleed the air out(you MUST get all of the Air out, because air just does not cool as efficient as Liquid), and remember all of our Temp gauges are inaccurate! My rule is "If it isn't spitting into the overflow(second)tank; it's NOT too hot. And it WILL spit if that pressure cap is not a perfect seal. All the best, Marlin.