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After replacing the thermostat the heater does not work

On my 2001 Ford Explorer, I replaced my thermostat and since then my heater does not work. I read something about a “air release valve”, but have not found very much information on it.

It doesn’t have an air purge valve. But you can purge the cooling system of air.

Get the engine up to operating temperature. With the engine idling, slightly loosen the upper radiator hose clamp. Take a flat bladed screwdriver and slip it between the upper radiator hose and the radiator hose neck. Allow the engine to idle until all the air is purged out of the cooling system. Retighten the hose clamp.

Tester

“slightly loosen the upper radiator hose clamp. Take a flat bladed screwdriver and slip it between the upper radiator hose and the radiator hose neck”

That shouldn’t be necessary. The 01 Ford Explorer should have a radiator cap.

Make sure your reservoir is already filled to the cold fluid line with the engine cool. Fill your radiator to the top when it’s cold and reinstall your cap. Turn your car on and allow it to warmup. Turn the engine off to allow it to cool down. Now you need to turn your radiator cap just enough to release pressure. Continue repeating these steps until your problem is fixed.

Also on many late model cars you need to jack the front end of the car, because of the location of the radiator the locked in air can be above the radiator. I don’t think that applies to the explorer though.

Good luck,

Geoff

The Motorcraft thermostats are very good and they have a jiggle valve to let air out of the block. Others might not work so well.

Not to assume anything, but are you sure you didn’t get the new thermostat installed upside down?

The thermostat was probably installed upside down. If purging does not work (make sure the coolant level is full) then have the thermostat checked. If it’s upside down there will be no flow. The engine will not overheat on short trips in the winter but it’s a different story in summertime. You won’t get 5 miles.

Not to assume anything, but are you sure you didn’t get the new thermostat installed upside down?

I don’t know about this car, but it certainly not be the first time someone did that. :slight_smile: