NO HEAT,HEATER VALVE WON'T OPEN,WHAT DO I NEED TO DO?

the butterfly valve should open and close, at your discretion, .being a 2000 model, it could work off vacuum , most australian & american cars of that era where / are vacuum operated , otherwise its has to be cable, or unlikely electric, with a solenoid .

but to answer your question, no, it should not stay open,

if ever you need to change your anti freeze, in the radiator, you should keep this valve open, as it will eliminate airlocks within the cooling system. .... if it is stuck open, 1st locate the valve, and check that it not look corroded, or damaged in anyway, you should see it activate ,when you have another person moves the lever inside , if not, look for a hose off, vacuum hose, will be a lil more tricky, as good chance it will be under the dash. . listen for hissing noises. .. the heater valve is not made to last forever, and do fail. .an easy buy from your after market auto store.

hope this info helps, kipp

check heater control valve.. or see if someone bypassed the heater core.. look for one hose going in the car and one coming out.. if bypassed it will be looped or plugged off...if you are not getting vacuum at the control valve it will not open....if you're control valve has a leaking diaphragm it will not open...need vacuum tester to check that...

OK.
Start by warming up the engine, and then shut it off when it is up to operating temperature, and open the hood.
Carefully feel the heater hoses to see if they are hot.
If you are unsure of which they are, ask someone who knows.
They are about 1 inch in diameter and are found at the rear of the engine attached to the firewall.
If they are hot, the problem is likely the flap inside the heater inside the car, which is controlled by a vacuum line or a wire cable.
Someone will need to dismantle the heater box under the dashboard to see about the air flap.
If they are not hot, feel the radiator hoses to see if they are hot.
If the radiator hoses are hot, and the heater hoses are not, you will next check the hot water shut off valve which is in front of the firewall, and in between 2 pieces of one of the heater hoses.
This valve is controlled by a lever on your dash board, that is marked hot or cold, and may have the colors red and blue on it.
Those valves usually fail by "sticking" closed, because lots of people only use the heater a few months of a year.
The valve is opened and closed by a wire cable or a vacuum hose.
If the valve works freely, you may have a "stuck" thermostat in the engine, which would not make enough heat to warm you.
Nowadays, engine thermostats usually stick open when they fail.
A symptom would be the radiator hoses and the radiator are warm but not hot.

Is coolant level full? To check if the heater core is circulating coolant, feel both heater hoses where they enter the firewall-both should be hot when car is at normal operating temperature. If only one is hot, look for a heater valve in the heater line-make sure it is open so the heater core circulates. Not all vehicles have such a valve, in fact, I think most don't have the valve, but you could check. The valve may be cable operated or vacuum operated to open and close. If no valve, and one hose is cold, there may be an air block in the heater core. Crack a line loose to get coolant circulating.
If both hoses are hot, it is probably the doors in the heater case not operating properly. Watch the door actuators when you move heat from cold to hot, and when moving from defrost to another setting. The temperature blend door is probably on the passenger side of heater case. These doors may be cable operated, vacuum operated, or electrical motor operated. If you watch for their operation, you might see or hear the problem with them not opening or closing properly.
Good luck.
If both heater hoses are hot

Hi thanks for asking. The thermostat is doing its job because it is supposed to open at 80c or 176f. If you are not in an extremely cold climate where the engine simply cannot maintain enough heat, then there is most likely going to be a low coolant situation or even a clogged heater core. If the temperature fluctuate wildly, though.. then you should look into the water pump drive system.
Let me know if you need anything else.twitter.com/acoates23234

check if both heater hoses going into firewall are hot.. if only one is hot then your heater core is stopped up..you can take both lines loose and take a water hose and back flush,,, force hose on one inlet of heater core for a minute and then the other.. keep going to you get a good flow...make sure heater valve is open, not just valve position take loose and confirm clear..last make sure your thermostat is not stuck open keeping engine from comming up to temperature

your heater hoses to your core are either bypassing the core or the valve is not working and stuck in the closed position.

Warm up the truck touch both heater hoses about midway in the hose . If one is hot the other cold you have no waterflow through the heater core. check the heater control valve it will be a valve in one of the heater hoses. usually cable or vacuum operated. make sure that valve is opening. if not, manually open it may be necessary to tie open to see if you have heat and if you get heat. If you do get heat determine wheather you need a new (control valve or cable or vacuum hoses. If you still have no heat chek the blend air door inside under the dash this is the door that changes the airflow direction from AC to heat it may not be working properly. Hope this helps.

The heater bypass valve is bad.It's located on the heater hose under the hood near the firewall.It looks like a little 3in.diameter black disc with a vacuum line attatched to it

Check the operation of the heater control valve. If it doesn't open up no heat. If the cable moves the control on the valve take the valve off and check it manually. The lever may work but the valve still doesn't open.