Heater doesn't really heat (???)

In 46 degree weather, mine is blowing hot air after 8 minutes. It probably starts blowing warm air 2-3 minutes after starting out in 46 degree weather. I use Auto and have it set at 70 most of the time. My route starts with a couple blocks at 0-25 mph and then I am on 45 mph roads with occasional traffic lights. I will sometimes turn climate control off for the first few minutes to allow the ICE to shutdown as soon as it can. I then turn it on when I'm on a main road and the ICE is on anyway and warm enough to still shutdown at a stop even with climate control on. It will get much colder here in the coming weeks and months but so far I am very happy with the performance of climate control in cold weather.

 

Huh? The car has a heater? <grins>

In North Alabama, we're not really getting all that cold, yet. But I've used it and anything over 74F is too warm for me but I've not timed it.

If I remember correctly, Ken@Japan published a chart showing the temperature output over time ... some Japanese sales material. It related to the exhaust heat recovery system.

Bob Wilson

 

You may want to check to see that your AC is inoperative, if the AC is active while Heat is required, the AC ON will mitigate its effect to some degree.

Check that your AC is OFF while in the Auto mode and Temperature is set to a Low setting.

David (aka Blind Guy)

 

Wow, I didn't think ECO effected heating... I thought only AC operations. I will have to try this on the way home tonight and see if it makes a difference.

We have been having single and below 0 temps for two weeks now. Still I get heat flowing in about 10 min and that is setting outside all day at work. I notice a very odd metallic smell during this time. Must be from the element.

Anyway, the Prius performs (heating wise) just as good or better than my 97 Camry in the same conditions. I have also noticed the seats seem to reflect heat really well. I am warmer sitting in these seats than any other vehicle I have owned.

 

You must have something set incorrectly. I was just speaking to Bwilson and sent him a PM, about how fantastic the new heater is in the 2010.

I am Normally in ECO or NORM and never have a problem producing HOT HEAT! It takes only 3 minutes to start to get warm. I set my Temp at HI in the extreme cold, and in 10 minutes of driving I am toasty warm. I wanted to see how it would perform. (This was in 25 Degree temps at night.)

I drove about 30 minutes sometime late night, last week, with TEMP @ and fan at about 3/4 full speed, and I felt like I was being COOKED. Not only does the car have a Great Heater, probably due in part to the Exhaust Recirc Mod, but it has a "Rump Roaster" on select models!

 

So far, I've only seen temps as low as 32°F. I usually just leave it on 70°F and <AUTO>. I figure (1) it's probably smarter than I am, (2) it certainly has more information available to it to make decisions and (3) I paid for it, so I might as well let it do it's job. And, I've been more than happy with the heater's performance (as well as the performance of the heated seats).

 

before you find out 'why' . . . first you have to go check it out, confirm your system works

many cars modernly run the AC compressor as a dehumidifier ... aint no point in having a nice hot car, if you have a nice hot STEAMY car, and can't see where you're going. similarly, if you're running AC, you're killing eco mode. so there you have it ... an answer to the 'why'. one thing the MANUAL won't answer, btw, is why folks read it as a last result ~


.

 

There is one thing I noticed about the heating system. If you have Auto engaged, the system tends to blow the hot air at your feet. If you really want to feel the hot air, press the Mode button until the icon shows the arrow pointing at your head. This will disengage the Auto feature, but will blow the hot air out of the upper vents where you can feel it.

So far it hasn't gotten really cold here in Austin, but the heating system has been blowing air which is too hot for me. I finally found out that I have to manually turn down the temperature setting to get it to stop blowing the hot air.

This system doesn't seem much different than my 2004 Prius. When the temperature got to around (or below) freezing, the inside of the car was always nice and warm.

 

I drove home in "Normal" mode (not ECO) and it made no difference on the time to hot air (TTHA) or amount of hot air. It was 0F and it still took about 10 min before noticeable heat came out. I did notice the ICE remained on at stop signs where normally it would have been off.
It was nice to feel the increase responsiveness of Normal mode again... I have been driving around in ECO to long.

 

Spiderman, at 0F, I have to wonder if you have any grill blocking in place.

 

Yes I do. The lower grill is 100% blocked. I did that early on (this fall) and it had a noticeable effect on FE.
If these subzero temps (-13F last night/for the last 2 weeks) keep up I may block the upper too.

 

At highway speeds I believe the car will produce more than enough heat to quickly warm the cabin. But if you start out in stop-and-go driving, things are a little different because the engine cycles on-and-off to conserve fuel.

I recently blocked 3/4 of the bottom grill and 50% of the top grill using 1/2" pipe insulation in preparation for winter. I figured this would help with a few things:
1. Reduce the warm-up time.
2. Improve fuel economy during the colder weather.
3. Keep much of the road salt and grime out of the engine compartment.

Then I got a bit nervous about possible engine overheating when I felt some really hot air coming out of the vent. So I purchased a Scangauge II and hooked it up a couple of days ago just so I would know what was going on.

It's currently set to monitor:
1. RPM's - The engine runs at about 1280 RPM when I first start the car in the morning and stays there while I'm out scraping the frost off the windows. Even while cruising along the highway during rush hour at say 45 - 55 mph, I find that the RPM's are often sitting at 1280 RPM, and typically don't go much above 1700 RPM. The engine never runs below 992RPM unless it's been turned off (0 RPM) and you're running completely off the battery.
2. Battery voltage is 14.6V - 14.7V while the car is running and charging the battery. I haven't yet checked the voltage in the morning for the not-ready accessory setting.
3. Instantaneous Fuel consumption. It's nice to have an exact number in addition to the bar-gauge that the Prius displays.
4. Water temperature. While driving in very slow stop-and-go conditions, the engine will cycle on and off based on the water temperature. In ECO mode, it turns out that the Prius will keep the engine on until the temperature hits about 135F and then turn it off until the temperature hits 114F. Once your speed picks up and the engine stays on long enough, the water temperature will eventually peak to somewhere between 190F - 195F. At 190F, the heater is kicking out a lot of heat from the vents while at 115F, relatively little heat is being produced. So far, I've only checked ECO mode, but I suspect that the temperature range will likely be higher with the other modes.

Anyway, I've decided that I had no reason to worry about overheating since 190F - 195F is the correct operating temperature.

Some things to consider that might help keep the interior warm:
1. Block the grill, at least partially and perhaps completely, depending on how cold it is outside.
2. Run the heater in recirculate-mode.
3. Install a block heater and plug the car in at night.
4. Consider taking the heater out of "Auto" mode since that mode seems to blow out a lot of luke-warm air. This is noisy and it takes a long time to heat the interior. I currently believe (although I'm not certain) that setting the temperature to a high setting and lowering the fan speed is the better way to go.
5. I don't know if the Prius has an electric heater assist and if it does, then I don't know how/when it activates. But if it were to activate unnecessarily then it would waste energy and lower fuel economy.

What else can you do when you start out in sub-zero temperatures during extremely slow stop-and-go driving? Assuming that fuel economy is very important to you, then wear gloves and warm clothing and keep the car in ECO mode.

Assuming that your comfort is more important than fuel economy, you have a couple of additional choices:
1. Don't use ECO mode until the interior of the car has warmed up. By using the other modes, the engine will (hopefully, since I haven't yet measured it) cycle on-and-off at higher temperatures. Once the cabin is warm, you could switch back to ECO mode since it's a lot easier to keep it warm than it is to initially heat it.
2. If it's extremely cold and if stop-and-go traffic is extremely slow, then consider shifting from "D" (Drive) to "B" (Braking). Driving in "B" will force the engine to stay on, allowing it to warm up faster.

 

Rrolff, you've fogotten to mention what you have your temp. set at. That will make a huge difference. We haven't gotten very super cold weather yet, but I've noticed mine starting to get warm within a mile of taking off. And this is driving slow out the subdivision, and then only driving 45 mph for the rest of that mile. Maybe just try bumping up your temp a bit and see if that helps.

 

We had a 46 F morning today and I had warm air within two minutes. I was in ECO mode.