I have a 2014 ES300h. If you turn the seats to high they will kick off in 15-30 minutes. They will come back on either after you have turned the car off or 30 minutes to 1 hour down the road. The dealer is telling me this is the way they are suppose to work but there is no mention of this in the owners manual or anyplace I have looked online. No one else seems to have this problem either.

 

Does your ES have an auto function for the heated and vent seats?

If it does, and it is set to be on, the heat and vent settings will cycle on and off.

 

I have heated seats in my IS but never use them, however, looking at it from the perspective of a rear defroster, which I'm sure we've all used, there has to be a time at which point the heater cycles off.
If the defroster or heated seats never turn off, then they will eventually fail if the vehicle is left running (or ignition on) long enough the very first time they are used.
Not the mention the harm to the person sitting on the seat, with regards to the seat heater.

For the heated steering wheel the Owners Manual states:

• The heated steering wheel will automatically turn off after about 30 minutes.

I can only imagine this would apply to the seats too as the principle of their operation is the same, and the construction is likely very similar.

 

On the IS, the seats will automatically turn down from the highest setting after they warm up. You can disable this feature by holding down both seat heater buttons at the same time, until you hear a beep. I have no idea about the ES.

 

Wow really? I didn't know that.

For the ES, I know it has its separate auto function for the 2016+ at least. Not sure about 2014.

 

I do have the Auto function for the temperature in the car but that is not always on when the seats shut down. The 2014 ES has a dial instead of buttons for the low, medium, high heat settings.