Opposite to Antifreeze.

[Rp0thejester]

We all add antifreeze for the colder months, with the way the climate is changing is there an antiboil for these 30degree heats that we are experiencing?

[GiveMeABreak]

A properly maintained coolant system shouldn't need anything added at all. They are factory filled with long life protection and should only need checking as part of regular servicing. A coolant is already designed to prevent freezing as well as overheating.

[Rp0thejester]

Okay, car had engine replaced before I bought it, so no idea if they put the correct coolant in. I'll ask in genuine parts.

[Paul-R]

My bottle of "radiator filler" says Anti-freeze and Summer coolant on it. So... nothing extra.

[Rp0thejester]

Okay, dunno what mine was filled with, hopefully not just water. I do have antifreeze in the glove box but topping up water with antifreeze is gunna take forever as I have no leaks

[Gibbo2286]

Change it to be sure, I had a young chap ask if he could sell his Hillman Avenger off my patch in late autumn, I asked if it had anti freeze and he said it had, car took a while to sell and after the first hard frost of the winter I found a four inch square piece of cast iron from the block lying under it.

[Rp0thejester]

Ouch

[Sloppysod]

Be careful of using 'tap' water to top up / fill your cooling system as some hard water areas could scale up easily.
Since my motorcycle days I have always used distilled or de-ionised water.