Problem: No heat from heater

<div class='quotetop'>QUOTE(bear15 @ Jul 21 2007, 08:05 AM) [snapback]482726[/snapback]</div>

Is the fan not working, or is there cold air blowing?

Tom

 

To help diagnose the problem, it would help to know if this is a first or second generation Prius.

 

Welcome to PriusChat, bear15. The above are good questions.

I'm going to assume you're driving a Gen 2. The climate screen lets you control the air conditioning system, which includes both heating and cooling. Assuming you are in the northern hemisphere where it is generally warm this time of year, your Prius is smart enough to not give you heat unless you really ask for it. Set the cabin thermostat as high as it will go and the fan on M. You should have heat and the Internal Combustion Engine (ICE) should turn on. Most of the cabin heat comes from the ICE, though there are two electric heaters in the coil.

And yes, there is a fuse, for both the fan and the electric heaters. The fuses are identified with their locations in your manual.

 

Fuse #17 located below the intr. panel/steering wheel, is the one you'd want to check.

I'm just curious, what temperture did you set in the climate control system when you tried to turn on the heat?

How long, or short of a drive did you make when you had no heat?

 

Getting the owner's manual *and* the Prius Maintenance Guide is highly advised. There's info in both you need, stuff that is not conveniently condensed in priuschat. They may be available in .pdf form somewhere, but it not then buy them from a Toyota dealer.

 

Hi All,

I actually have the reverse problem. And wish there was a button like the A/C button on the Climate screen to disable the heater.

Driving home in high 80's F weather, I have the AC enabled and set to 80. Then I get home, and disable the AC.

In the morning, I start up the car, and forget I left the automatic temperature set to 80 F. And a few minutes down the road, wonder why its so warm in the car, when its 50 F outside!!

If there was a Heater button, I could disable heat all summer - which would allow me to stay in automatic more often. Instead, on the 45 degree mornings, I just turn off automatic controls off, and set ventilation to recirculate. Warms up in minutes. All that electronics - ya know.

Being near the ocean, the Japanese probably do not realize some areas get the highly variable Afternoon to morning temperature changes.

 

The heater doesn't come on unless the temp you select is above the temp in the cabin.

I use the Auto A/C button on the steering wheel, and turn it off when I get home. Easy and works well for me.

When you hit the Auto A/C button, the MFD tells you the temp that is currently selected. I usually never have to select 80 degrees here in the Seattle area, even when it's really hot, I find 75-78 works for me.

Again, just use the temp toggle on the lower left of the wheel to turn the temp down after you hit the Auto A/C button. And you don't want to use recirculate unless you're running the A/C or the inside of your car will eventually fog up.
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Actually the climate in Japan varies hugely from Okinawa up to Hokkaido. And yes it does get cold at night and warm in the daytime, at least in the Osaka area.

 

Ed,

Bill Merchant's comments, to which you've already replied, are right on target. If you follow the steps he suggests and you still don't get heat after driving a couple of miles, something's wrong.

Before you take it to your dealer, make sure the air vent is open and not set to recirculate. There's a thumb button for this on the lower right part of the steering wheel. I've found that if the vent is closed, I only get a trickle of heating or cooling.

(BTW, the Prius's air vent closes really tight, and you should not drive any distance with it closed. It's meant for things like a brief stretch of foul air or a dust cloud. With the vent closed, a leaky exhaust could present a serious carbon monoxide hazard.)

The Prius has a really good integrated climate control. When it's working right, after you set it to the temperature you want, you should be able to mostly forget it, winter and summer, except for an occasional tweak for special situations. If that's not happening for you, and your vent is open, I would suggest taking the car to your dealer for help.

 

<div class='quotetop'>QUOTE(bear15 @ Jul 22 2007, 09:48 PM) [snapback]483354[/snapback]</div>

Just as an experiment: You should be able to get into your Prius, put it into IGN-ON mode. (No foot on brake, and two presses of Power button.)
Now, select the Climate control screen on MFD. Turn the Climate control to ON with you steering wheel button and run the temp. all the way up to HI. You should hear/feel the vents direct air to your feet. Reach down under the dash, in the proximity of your right leg, and find the airflow. You should be able to feel "warm" air rather quickly.
Does this happen?
If not, something may be wrong with your elec. heating coil. or airflow actuators.
Now, if that works, you could go one step further and put her in READY mode, and go drive (leaving climate control where it is). Within 10 min of driving it should really warm up and that verifies your thermostat is working and warm ICE coolant is reaching your heater core.
If not, have it checked out.

 

Hi donee,

I want to caution you about driving with the vent set to recirculate. The Prius's vents are really tight, and any leak in the exhaust system could expose you to carbon monoxide. I've had experience with this in a previous car, and believe me, CO sneaks up on you.

I agree, it should be possible to disable the heater. But my previous car limited the output of the AC by running the heater at the same time, and I'm sure the Prius does the same. This seems wasteful, but it eliminates the need to cycle the AC on and off and makes it easier to maintain a comfortable temp inside the cabin.

Given this fact, you may as well set the AC to whatever temperature makes you comfortable and forget it. If you stay focused, you can still get excellent mileage. We keep ours at 72 F year-round, and we seldom have to ajust it even with outside temps ranging from 110 F down to 20 F. Our mileage ranges between about 50 mpg in summer down to about 46 in winter, despite several steep 2-mile hill-climbs a week.

 

could be the blend door actuator- a servo motor.

remove the glove box, turn the fan on low. start with your temp on high and decrease the temp by pressing the little arrow buttons. while you do this, listen for the sound of a small electric motor. if you hear this, then the motor is ok. if not, there's your problem.

 

Hi cwc, welcome to PriusChat. The Prius air cooling system runs off an electric compressor, which can adjust the amount of cooling it produces as demand warrants. Unlike other cars, the compressor can run whether or not the ICE is running. The air conditioning system works best when you let it be automatic, as I think you do. The cabin air is filtered and conditioned for heat or cool based on the thermostat setting. The system has a humidity sensor and will dehumidify the air if it is moist, running both cooling and heat. It does not heat the incoming air if it is above the cabin air temperature unless dehumidification is needed. It has a solar sensor (that bump in the dash next to the windshield on the driver's side) to increase the cooling if there is a lot of solar heating.

Because the HV battery works best at temperatures a person is comfortable at, it is cooled or heated by cabin air flowing through the grill by the passenger rear sear, across the battery, and exiting under the right-rear quarter panel. There is always airflow from outside through the cabin, even when the recirculate mode is chosen. In very hot weather, running the air conditioning system can actually improve MPG, in certain circumstances, because the battery will be at a better operating temperature.

I, too, have had some experience with carbon monoxide (CO), though not in a vehicle. If anyone ever feels woozy or tired while driving, stop the car and get out and walk around, it could be CO poisoning. If you feel better after a few minutes, and need to keep driving, keep the windows open! CO is insidious, odorless, and deadly.

 

<div class='quotetop'>QUOTE(bear15 @ Jul 24 2007, 07:56 AM) [snapback]484072[/snapback]</div>

Great! Do you know how the bubbles were formed?

 

<div class='quotetop'>QUOTE(bear15 @ Jul 24 2007, 05:56 AM) [snapback]484072[/snapback]</div>

How do you bleed the radiator? Or was it the refrigerant that had the bubbles?