why have i had to replace the thermostat 7 times and my heater still doesn"t work? I have only put 61000 miles on the vehicle.

Have you checked any other possibilities, such as a broken heater valve, blend door stuck closed, or air trapped in the heater core?

Why? Because you’ve been changing the wrong part.

Can you explain better?

State The Model-Year Of This Vehicle.

Who has put in 7 thermostats ?
What brand are they ?
After thermostats 2, 3, 4, 5 , and 6, did anybody have a suspicion something was a bit odd ?
What other diagnosis of “no heat” has been done ?


once i replace it with a new thermostat the heat starts working fine.but but not long after it stops blowing warm air.

no,it diagnosis faulty thermostat every time.

I Wouldn’t Blame That Bunch Of Thermostats.

Sounds like you’re getting air in the cooling system. When you open it up to change thermostats, you’re purging the trapped air (Thermostat housings are ussually near the top of the cooling system and air rises in liquid).

After a couple of drive cycles, you’ve got air surrounding the thermostat. Then, no heat.

You need to find the source of air entering the system. The system is supposed to be a closed loop. Your loop is open.

A cooling system pressure test is a start in the right direction.

Are the radiator and coolant recovery tank always full to normal capacity when you check them after “no heat” begins ?


Reinstall the current thermostat with a bead of RTV in the slot that the thermostat rests in along with a new gasket.

I kinda shake my head with thermostat replacements. For many cars they are so cheap that you might as well go ahead and replace them. They are also so simple I really don’t understand why they get replaced so much (perhaps because they are so cheap) but I bet many are “A OK”. Now BMW has a “feedback” thermostat and at times it sends the wrong data, perfectly good functioning thermostat but fails in an electrical sense. People sure get told to replace thermostats of all types quite a bit.