heater does not get hot

The more I look into this the more I think I want to make
the heaters already in the car work when I want.

From the manual it looks like they only run when the coolant
is quite cool, and you have set the temperature control to
max heat and are using floor heat.

If they were mod'd to turn on without heat to max, you
would still need to interlock them with floor heat modes,
because they are in that part of the
ducts apparently and need air flow there. No idea
how to do this part.

Meanwhile is everyone that is cold turning heat control
up to max temp?

 

With heat turned to max, the engine will not shut off as easily as with heat set to, say 68 degrees. The electric heater is floor only, but I was under the impression that it did not require that the heat be set to max. Are you sure it does? Does anybody know?

 

Hi Daniel:

Well, if worse came to worse, I could wear the thermal underwear. But jeez, what a PITA to have to change at work and again before I leave!

I had assumed the MFD used a capacitive touchscreen, so any form of cover over your fingers (Mittens, gloves, etc) would interfere with target-box selection. Still, at least the mittens keep my fingertips toasty.

Tell me about the rain. We had freezing rain and ice pellets Thursday. That changed to snow later in the afternoon. Blizzard conditions since then. Looks very nasty out there. I have two balconies, one enclosed and one open, and the drifts are piling up at the patio door.

I have today off anyway. I was planning on a drive out to the hobby farm over the weekend, but given that the Trans Canada is closed west of Winnipeg, and they're warning you to stay off east of Winnipeg, I'll just stay here.

I've discovered a cup of hot cocoa and a gas fireplace is almost as good as a cup of cocoa and a real wood fire!

Happy New Year!

 

I don't know how the touchscreen works, but gloves are not a problem. However, a very light touch does not work. You actually have to press, just a little (not much).

The place I was at in BC (Mountain Trek, a mountain hiking health spa) has a fireplace insert. It sits on the hearth in front of the fireplace, jutting out a little bit into the living room. And it burns wood. It's wonderful. Glass doors give it the best of both systems: the efficiency of a Franklin stove, but you still get to watch the logs burn. I wish I had one. Just one of the few disadvantages of living in an apartment.

When I lived in the country I had a gas parlor heater. I could watch the gas flame through a small window, which also radiated heat by way of special ceramic inserts. It was nice. But unlike a wood fire, it never changed.

 

Daniel:

I think I know which fireplace insert you're talking about, the ones I've seen are made by Napoleon. They combine the "best" of both: airtight wood stove with ceramic door, so you can feel the radiant heat and watch the flames.

I have a Regency airtight wood stove in my hobby farm, for "emergency" use. I like to use it just to feel the heat and watch the flames. The cat appears to like it too.

Though most gas fireplaces don't look "real," I'm satisfied with the Regency gas fireplace in my condo. You can arrange the ceramic "logs" to get a good effect.

 

around here where woodstoves are common, you never see what you are describing anymore...

visible flame means the stove is operating inefficiently. sure a flame looks cool but that only means that its spewing polution out and violating state guidelines on polution levels (you will be fined if you are caught)

i will say that you cannot beat the feeling of a warm fire though

 

I'm only telling you what the manual says. Too warm to check right
now here. It is only software after all and they could have fixed this since! I got a 2005 car but my manuals are 2004 since I bought them
before I ordered the car, so my manuals are early printings.

Manual says for electric heat the following must be met:

"cooling water temperature is below 55 C (131 F),
setting temperature is MAX HOT,
air outlet damper position is FOOT or FOOT/DEF,
and blower switch is not OFF"

Reference the section "PTC HEATER CIRCUIT" page 05-1371 of the
owners manual "2004 Repair Manual Preparation Specifications Diagnostics Volume 1

And just in case Toyota reads this stuff here is how I would design it to work for my cold climate:

1 Have dual sets of ptc heaters, one for floor and another pair for defrost. OK to use only one pair with priority for the defrost one, if not enough power for both sets.

2 Enable the electric heat either with a user switch, maybe an instant max heat switch that times out after 15 minutes, or else do the enable based on the other stuff plus when the temp in the car is greater than 5 degrees below the set point on the thermostat, and outside temperature
is below say 20 degrees F at speeds below 50 mph, or below 5 degrees F at any speed. Just guessing on temp points, but make it automatic and make it work for all conditions not just Arizona in the summer!.

 

I have a 2004MY Prius, so your service manual applies. I usually drive with the floor/def. That is, the MFD Climate page, right most target box selected. In this sort of weather, Max Hot is usually selected.

I would hazard a guess that at -30 C or colder, the coolant temp is nowhere near 55 C, especially in city traffic at speeds 60 km/h or less. As Daniel has mentioned (He lives in Fargo so he knows what extreme cold temps are like), Toyota missed a huge opportunity to have a serious auxiliary electric heater.

Since Danman confirmed the A/C compressor is variable speed, run off the 200 VDC NiMH battery pack, for about the same electrical consumption a 1,000-1,500 watt 200 VDC auxiliary heater could have been used.

Now that the ICE is running much longer to maintain temp, my SOC is almost always Green. It's never more than 3 bars from the top of the scale. So it wouldn't be a huge drain to run a serious electric heater.

In more moderate temps, say 0 C or warmer, what irks me is that the Prius can initially heat up the interior much faster than conventional vehicles. At sustained temps of -30 C or colder, forget about it.

 

i think its safe to say that for extreme weather driving, the Prius is not a good choice. i never run max heat, i would be roasted out. i rarely get it above 70º F which is more than warm enough for me.

but i live in a reasonably mild climate and i can see Toyota's reasoning for not adding a bigger heater. in most kinds of weather, its not needed. i think they considered and discarded the possibility simply because of the numbers involved.

although they have no official position on distribution, its pretty obvious that certain areas of the country are favored heavily and they all have mild climates.

i dont recall a lot of people complaining about an ineffective air conditioning system and i went through the hottest summer ive seen in my 18 years here in WA st very comfortably.

looks like aftermarket solutions will be the best avenue for resolution. i really dont think that Toyota will do a lot to address this issue. i maybe wrong and in the world I want to live in, there would be special extreme weather packages available as options.

but the Prius has achieved its numbers by not wasting energy it produces heedlessly.

 

I think Toyota didn't realize how big a problem it would be to
get heat in cold weather in city traffic. Also there are some
cost issues.

Powering the heater from the 200 volt battery would be a
safety issue since that would bring the HV to another place
and inside the cabin under the dash where it would be
especially bad in an accident. The cabin and HV are pretty
well separated by steel currently.

More could be done with the 12 volts but that would require
a bigger converter. I just noticed there is an electric
heater for PS as well that together with the car heat electric
looks like it loads the converter pretty well.

Be interesting if anyone can measure the heat on full
converter current load. Maybe someone with a scanner
can read it out?

I mentioned adding some of those 300 watt heaters I
see for RV's etc but now I am not sure there would be
enough power for them too.

Maybe Toyota or some accessory mod house could make
an add on heater with maybe 24 volt converter for power
that could be safely added. This would keep the bad
voltages in the engine compartment and we'd all get a
double benefit from any electric wattage. We get the
electric heat and then we get more engine heat too from
the engine running more to charge the battery.

 

This is too broad a statement. If "extreme weather" means deep snowdrifts, you may be right. But for cold weather, no car on the planet starts as easily and reliably as the Prius.

The only cold-weather-related problem is the length of time it takes to heat the cabin in sub-zero temperatures and the reduced advantage compared with conventional cars. (I.e. instead of double the mileage, it maybe gets 1.5 times the mileage.)

The Prius is still the best choice, unless you need more power (towing), bigger size (large family or hauling) or AWD for deep snow or off-road. After 20 or 30 minutes it is toasty warm. The problem is that some of us seldom drive that much. In Fargo, the only way to spend that much time in the car is with multiple errands, because in 30 minutes you can drive all the way across town and back.

 

For the colder climate folks, this is a great thread!

I didn't realize that "Max Heat" needed to be selected to activate the supplemental electric heater. This certainly isn't intuitive. (Well, it might be intuitive to "some," who despite numerous discussions, still persist in turning the household thermostat up to 90 degrees to warm a cool house "faster"...)

When the temperature is sub-zero,
And Toyota's heating, it lacks,
Don't diddle with the auto-temp,
Just set it to Max!

 

Daniel said it best: in an otherwise PERFECT car, the only thing lacking is good heater performance in frigid temps, especially -30 C or colder.

To address some comments made above:

Toyota actually mentions "HD battery, alternator, and heater for Canadian climates" in the brochure for every other car/truck they sell in Canada. I had a chance to go for a ride in a 2004 Toyota Echo Hatchback (Yaris in Europe) and that car will keep you toasty.

I doubt it would be that much of a safety issue with a 200 VDC heater in the plenum. BMW offers an explosive bolt to forcibly disconnect the positive terminal in an accident, perhaps the same technology to ensure safety in the Prius?

Since the 12 VDC current output is extremely limited, I don't think that's a serious option. If you have 1,500 watts at 12 VDC, you need 125 amps.

 

HAHA I like it! Just be thankful you don't have to live in a climate like mine.

Actually, some heating systems DO heat faster if you crank the heat up more.

I have a Bryant Evolution 90i Plus gas furnace at my hobby farm. It has a variable speed fan, variable speed induction, and variable fire gas burners. It's controlled by their "Evolution" home network, which to me looks very suspiciously like the DeviceNet industrial protocol. Even the color-coding for the 4-wire interface is identical.

There is also an ODT (Out Door Temperature) sensor mounted - duh - outside the basement wall. The furnace uses the Evolution indoor thermostat and the ODT to adjust - fine tune - the PID heating loop.

PID - Proportional deadband, Integral, and Derivative. Lot's of fancy Calculus to determine how best to adjust OP (Output, in this case the burners and fan), to have the PV (Process Variable, in this case the actual room temp) as close as possible to the SP (Set Point, in this case the desired room temp).

In almost all cases, the furnace runs the blower fan at the lowest speed, and the burners fire at the lowest flame, if the PV is within 3 degrees F of the SP. That saves you an incredible amount of money when heating. If I want to quickly heat things up, I'll set the thermostat to 82.

The burners go to High Fire, and the furnace blower ramps to its highest speed once the heat exchanger warms up. The interior temp will quickly ramp, then I'll restore the previous SP. I rarely fiddle with it though, the autotuning PID loop seems quite reliable and intelligent.

I agree the supplemental electric heat is NOT intuitive or clearly explained. It was actually my Prius-certified Tech that explained that one to me.

 

All this talk reminds me of the car I went to college in. It got to -30 F
some mornings and my Saab was about the only car in the parking lot
that always started. (2 cycle, no crankcase oil).

It also had a too small heater and I had to wear gloves etc and shiver.

So now I have come full circle except the Prius heater is way
better than that Saab had. We've all just been spoiled by cars
with oversize engines and extra heat to throw away.

I bet Toyota could add an option package to add on and fix this
though if they got enough complaints! Shouldn't be that hard to
boost the converter to 150 amps if necessary, or try the 200 volts
in a safe way as others have suggested. As we've all figured
out here the power is there to fix this, and without going to an
add on gas heater like the old VW bugs had.

Meanwhile I agree with Daniel, after driving 3 different diesels that tend to run nice and hot it is great to have a car I can start when it goes well below 0

 

There should be no safety issue with a 200 volt heater: just have the heater in the same compartment with other high-voltage components - or even right in with the battery, since it will only be used when everything, including the battery, is cold. Then run a pair of insulated vents to the cabin for hot air and return air.

I'm sure we are not going to get a retro-fit. But they could offer a cold-weather package on future models.

 

Well if somebody is really adventurous and safe around high voltages: I like the battery idea for a location. 208 volt household forced air heaters should be close enough to work just fine .......Plus you can zap any rear
seat drivers!

Lucky for me it is warmer here than for many and it gets below 0 F only a few days a year at worst. So my immediate fix for heat is ready to try!

I now have a hybrid Prius that looks like a hybrid! I added a Marinco plug
similar to this: Catalog No. 150BBI.RV
that is mounted right to my rear bumper.

Easy install!

Case anyone wants to try this at their risk of course:

Note the following:

1 I used the bumper because it is easy to drill into plastic. Also should
add less drag than side mounting. I used a 1 7/8 inch hole saw.
Plenty of room inside that bumper, really just the bumper cover.

2 Make hole above the real metal bumper inside. You can get under car
enough to see in!

3 I put mine to the right of center. You want to avoid the center spot which belongs to the keyless entry antenna!

4 Then connect cable and run into the car via the antenna rubber grommet. Hole is plenty big in the car metal, just need an extra hole in
the grommet!

5 I used a regular 14 gauge extension cord and have 3 outlets in the
hatch area which I will use for:

pre-heat
light when working on car at night
refrigerator when parked for night in summertime
and a battery charger I will be building into the car (for the fridge
battery mainly, after it is heavily discharged but will work for maint. for
both batteries, if I have to leave car for a while.)

So my plan for winter is to set up the heater and plug in on cold mornings
while I eat breakfast. Car should start warmer, engine will save heat
for catalytic converter more, and the battery will start out a bit warmer.
Plus on icy days scraping will be easier!

 

To clarify: I am not suggesting anyone mess with the 200-volt ststem. I am saying Toyota could design the next model with a 200 volt heater without introducing high-voltage circuits anywhere they are not already in place.

 

There would be no safety issue with a 200 VDC heater in the plenum. I wonder if folks raised the issue of "safety" when automotive electrical systems changed from 6 VDC to 12 VDC? Hey, they doubled the voltage ... yikes.

I feel perfectly safe around industrial electric heaters, and those things are 3-phase at 575 VAC. A reasonably sized 200 VDC heater would only need around 7.5 amps, and appropriate over-current devices would be installed to limit the possibility of stray voltages.

Battery source voltages can be inherently dangerous, as the short-circuit current capability can be very high. It doesn't matter if it's 12 VDC or 200 VDC. Ever seen the aftermath of a grease monkey dropping a wrench on a battery?

 

the post reads like the heater would be sitting in the drivers lap...ever heard of duct work?, the heater could be put nearly anywhere.