94 Honda Accord over heating

My 94 accord ex keeps over heating, the thermostat has been changed twice in the last 6 weeks. (the first time was for the overheating, the second for the same reason, it was installed incorrectly the first time) I’m not losing any fluid and when it does get hot there isn’t any steam or any sign of losing any fluid (not smelling any coolant) at any time. The fans are working properly and the oil levels are fine. I have paid three different mechanics in the past 6 weeks and keep getting different answers. And, one of them found and resolved an air pocket in the head. The weird thing is that it’s not over heating consistently, usually only after I’ve been driving for about 45min to an hour. Any ideas? Please!

What are the symptoms, or indications, of OVERHEATING?

It could be air in the cooling system, or your radiator is plugged or damaged, or your radiator cap isn’t working right, or your water pump might be going, or, if the engine’s seriously overheated before, your heads could be warped.

My suggestion is to do the following, in this order:
1)Remove air from the system - when the engine is cold, remove the rad cap, start the car, and turn heater and fan on high, let the car idle for 5-10 minutes, this should allow any air to be expelled from the system.
2)If car still overheats, replace rad cap (or do this anyway, it’s not very expensive and won’t hurt anything)
3)Check all hoses (actually, maybe do this one first.) Make sure they are all tight and in good shape - not cracked or torn. Also make sure the lower rad hose isn’t collapsing under the vacuum of the water pump - obviously, this must be checked while the engine is running.
4)If still overheating, get a cooling system flush (again, you might want to do this anyway if it hasn’t been done recently)
5)If still overheating, you may need to see a mechanic, I’d say, because your radiator or water pump likely aren’t working right.

Also, just a random thought, if there’s no other signs of overheating than the gauge in the dashboard, then maybe the coolant temperature sensor is faulty. I don’t know how much they are, but it could be worth investigating further.
Good luck.