heater needs to be set to 80+ for heat after AC repair

An AC creates cooling... It's 80 degrees in most of Oregon today and You're concerned about the heater (which is an entirely separate system) not working? Clearly you're a dishonest robot plotting to spam us in future posts. Or have I misunderstood and you have a reasonable logical explanation?

 

You're heater hoses to firewall should be quite warm three min after start up if this is case system making heat just fine. You not getting it on to cabin is another issue . Deal with later .

 

First, I would check for any codes from the HVAC system. You can do that without a scan tool, if you scroll down to "Codes from the heat/air conditioning system" on this page:

Blink (a/k/a Flash) Codes – How to. | PriusChat

Next, I would watch A/C system live values using a scan tool, paying particular attention to what it thinks the interior cabin temperature is. It will only heat when your temperature setting is above what it thinks is the cabin temperature (unless you go to a temperature setting of H᠎I, which heats unconditionally).

The cabin temperature reading comes from a sensor roughly above the driver's right knee.

Edit: the PriusChat software doesn't think we should ever say H᠎I to each other, so it 'fixed' my "temperature setting of H᠎I" above in a way that didn't make any sense.

 

Yes and as I've mentioned before that sensor above your knee it's a lil grille in plastic . That thing will fill up with General schite and dust and pet dander . Whether you own a pet or not so blow that thing out with air .

 

If it's 80 out and you set to 70 degree heat uhhh likely ya not gonna get anything out of vents.

 

The thing that's going to determine the heat behavior is how your temp setting compares to the inside cabin temp, not to the outside temp.

 

Yep... Remember that time in near freezing weather an OP posted that their heater wouldn't work anymore and it turned out they always ran their heater at lowest setting and didn't understand that in cold weather you need to turn the heat up?

None of this makes sense to me because if its cold out I run heater as hot as possible and turn it off/down when I'm too hot. And if its super hot out I blow coldest possible AC air on my face until I feel cold.

As in, setting the inside of your tiny car interior to a specific temperature and expecting that temperature to be as stable as it is in your house is so incredibly stupid I'm just going to shut up and not say anything else.

 

I am pretty sure if its 80 outside and I set the system to 70 or 75f there will be no heat. The system does consider the outside temperature along with the cabin temperature.

If its 60f outside and I set the system to 70f, I will get heat IF the engine is warmed up.