Hello does any know's what the heater water control valve is used for and can i take it out.

 

Its used to shut off the hot water going into the heater core. If you live in an area where you NEVER need heat then you can simply bypass it with a U fitting. Otherwise you should replace it with a NEW one.

 

My guess would be the valve could be eliminated, with the use of longer heater hoses. '98+ don't have the valve.

 

if you take it out you will have hot water to the heater all the time, in other words no control over heat, 24/7/365 heat. If you make a loop between the two hoses then you just eliminate having heat at all inside.

 

Always post the year/engine of your XJ for the most accurate replies.

I'd recommend replacing it. Not particularly expensive and the plastic on the old ones deteriorates over time and they can break, resulting in loss of coolant and a possible overheat.

Team Cherokee is a good source for a replacement.