header tank hot

[royzart]

The coolant or header tank on my van gets really hot
and boils,but the temperature guage still reads normal
there is no loss of water and the fan is still working
does anyone have the answer please

[chadad]

If there are two hoses, one large & one small between your header tank and the thermostat housing, then remove the small ( half inch thick ) one and make sure that it is not blocked. As this tube allows air to escape when filling the header tank.
If there is no small tube then slacken off the top hose from the radiator enough to allow air to escape, top up the header tank until coolant leaks from the loostened top hose, tighten top hose and all should be well.
REMEMBER , DON'T DO THIS WHILE THE ENGINE OR WATER ARE HOT.