I have a 94 lexus that is blowing no heat.I have changed the thermostat,removed the control valve,changed the raditor fluid,bleeded the cooling system.But still have no heat.checked the heater core by checking the passenger side floor but thats dry.very confused any suggestions

You must wait for the thermostat to open up, crank your heater on full, you will get only cold air once the thermostat opens it will start to heat up, heather runing wait for thermostat to open youll see your coolant bottle bubble up and go down , then you loosen the bleeding valve if you got one, cooling system service should be done all together , change thermostat,flush the coolant system, replace hoses if needed, if thermostat is shut and wont open up your more likely will blow a hose from the pressure .ty

May need to bleed the air out of the system after the hose change. Look for small bleed valve on the top engine or cooling hoes/pipe bleed slowly while engine is at operating temp, then refill after reservoir after car cools down

You have problem in 1) Your air flow system have gone down and some plastic valves that opens to cold position or to hot position is broken. Solution: remove panel and check this plastic valves that controls airflow.
2) Your heat salon radiator is very poor and can't blow in all directions. Solution: replace salon heat radiator.
3) Your cooling system don't have good limit of coolant. Solution: fil it to min - max position.
4) Your cooling system isn't bleeding. Solution: make system without air in it.
Hope this will helps.

Did you put thermostat in correctly? cooling system should eventually bleed itself of air, you will just need to keep filling. Make sure your not adding straight coolant/antifreeze.

What engine 2.2 or 2.4 ?
Important: On vehicles equipped with the 2.4L engine, open the coolant air bleed valve. The coolant air bleed valve is located on the top of the thermostat bypass pipe/heater pipe assembly. Close the valve once a continuous stream of coolant is expelled from the valve.
Does the cooling fan come on ?
Notice: When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 50 000 km (30,000 miles) or 24 months.
Close the radiator drain ****. Remove the drain hose.
If previously removed, install the engine block drain plugs.
When installing the drain plugs, use pipe sealer GM P/N 12346004.
Important: On vehicles equipped with the 2.4L engine, open the coolant air bleed valve. The coolant air bleed valve is located on the top of the thermostat bypass pipe/heater pipe assembly. Close the valve once a continuous stream of coolant is expelled from the valve.
Fill the surge tank to the base of the filler neck.
Start the engine with the pressure cap off. Let the engine run until the upper radiator hose starts to get hot.
If the coolant level in the surge tank is low, add the proper mix of coolant until the level reaches the full cold line.
Important: After servicing the cooling system, and if the vehicle is equipped with an intermittent low coolant light, an occasional low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the full cold line when the system is cold.
Install the cap onto the tank with hand tight pressure.

Have the cooling system pressure tested ! 3.1 l engine These engines had intake gasket problems , have the radiator cap tested as well . Bad radiator cap will allow coolant lose . Does the oil cap have whitish or dirty color foam on inside ? Coolant leak into the oil .

Yes, Drain the cooling system to a level that is lower then the lower rad hose and where it meets the engine at the thermostat housing. Disconnect the cooling fan switch at the housing and squeeze the hose clamp flanges together to remove the radiator hose from the housing.Then remove the retianing nuts from the housing cover. Once removed note the position of the air bleed valve of the old thermostat while in the housing (bleed valve hole is normally on the top /facing up) Pull out thermostat and gasket. Note that the rubber gasket fits over/around the edge of the thermostat. Replace with new thermostat and gasket making sure the air bleed valve is in same position as previous and spring end is directed into the engine. Install the cover and bolts and tighten/torque accordingly. Reattach the hose to fitting and tighten hose clamp and reconnect cooling fan connector to end. Restart engine and allow to warm up sufficiently and check for leaks and heat in cabin compartment. Done. good luck.

if there is no cap on the radiator, fill the recovery bottle and open the bleed screw until coolant sputters out of it. the bleed screw/ valve will usually be at a high point of the cooling system e.g. intake manifold or thermostat housing. be careful of hot fluids!

Need more information. The most important thing would be to watch the heater water valve move when someone turns the control from hot to cold, back and forth?
Heater valve controls tend to be operated by vacuum, and switched by a heater computer. Lots of possibilities. But first tell us what you see move when operated? Valve is usually in engine compartment, in the heater hose. Follow the hot one.

make sure your coolant fluid level is good, than check the valve that controls the amount of coolant that flows to the heat exchanger inside your dashboard, make sure it is wide open. (find it by having someone inside the car move the heat control from hot to cold and back while you are under the hood looking for the valve. Sometimes the cable that goes from the dashboard heat/temp control to the coolant valve comes off.