Heater core

the air going thru the heater core should be cold going in and hot coming out. the coolant going thru it should be hot going in and warm coming out. it could be a bad core, but you should get a second opinion and price. try a local triple a mechanic? you shouldn't need a hybrid specialist for this sort of thing, although, there maybe some special requirements when replacing the coolant, i'm not sure, i might be thinking brake fluid. certainly get your local mechanics opinion.

 

Thatss what happens, if you don't change the collant every two to three years. Something in the system evidently corroded, and the residue most likely clogged the heater core.

Depending on where it is under thae dash, it might tahe 5-10 hours of labor. So, $1200 might be what it will cost to replace it.

 

My opinion is that the heater core coolant pump should be checked to verify it is operational, prior to going to the trouble of replacing the heater core. If your local dealer's service dept is unaware of the existence of this pump, find another dealer.

How many miles on the odometer?

Note that the original pink Toyota Super Long Life coolant is good for 100K miles.

 

The following is unlikely to be the OP's issue, but it could be.

The Gen II Prius does not have an engine temperature gauge (although it easily could and should have one).
so we really don't know what the temp is without additional equipment (OBDII scanner/readers).

I had a Camry once with a stuck open thermostat. The temp gauge reading remained just
above the cold mark no matter how far I drove and I had no heat until I replaced the thermostat.

 

There are several used car dealers in the Raleigh/Durham general area that sell quite a few Prius' a year. They get them worked on somewhere. I would look on Craigslist to find them and call to ask where they would recommend taking it.

 

Sounds like the coolant transfeer valve is stuck/bad
This is a 3 port valve on the drivers side next to the radiator (on the drivers left of radiator).
It directs engine head coolant to either thermos storage container or heator core...
There was a report about a year ago of no heat... he replaced valve and reported sugsess..
He purchased some sort extended hose clamp removing tool.. but had to drain coolant...and as you might have read
getting air bubbles out of coolant system is no joy..

The documented functions of the valve are PREHEAT where heater core is blocked off allowing thermos coolant to only enter
the ice.
The next valve function is ENGINE WARM-UP where the valve blocks flow to the thermos bottle and opens flow to the heater core..................................
The next valve function is DRIVING where flow is both to heater core and thermos bottle.....................
The next function is POWER-OFF where the thermos bottle route is closed the same as warm-up position.................

If you drained coolant prior to no heater condition then you should suspect air bubbles .... however if you havent drained coolant
check into coolant transfeer valve... When bad the dealer can read codes but only dealers code seem to read codes for bad transfeer
valve..

There is also an electric heater coolant pump that operates when gas engine stops and heater system is on...

Hope this helps..

I'mk trying to attach pdf file shows prius cooling system hope this works

 

There does not seem to be any problem with coolant in the Prius, as far as PC'ers are reporting, that indicates frequent changes are needed. But that assumes Toyota SLLC is used. It would be good to change to that. It may be that, as posted above, the valve is stuck. I'm guessing that the SLLC may have better lubrication properties, to help keep such valves working.