heater does not get hot

Depends on how cold it is, how far it is and how long it takes to get there. I haven't had a problem yet, but it has been no colder that 14F so far for my Prius.

When it was in the -10 to -20F range, my 15 minute drive to work in my '95 Odyssey was mostly cold. Your BTUs may vary.

The car tries to take care of the environment first by getting up to temperature. The U.S. models have 2 small cabin ceramic heaters, I think the European models don't? Could be wrong.

 

i'm not getting great heating performance as well.
it takes about 15 minutes for things to get going

 

I've noticed less than stellar performance from the heater on cold days as well, as discussed in a post earlier this month.

http://www.priuschat.com/forums/cold-weath...html?highlight=

On a very cold day, the output on my heat vents was "warm", but not "hot". This is a CRUCIAL difference in keeping the car warm and keeping the windshield clear on these very cold days.

I talked to my service scheduler, and she told me that the Prius is build and supplied with one thermostat only (you can't ask for a warmer thermostat).

I had the service tech check the car and was told that the thermostat is functioning as it should. I am following up with the Service Manager to find out if a "Winter Front" is recommended. I also have committed to plugging in my Prius on a timer when it is quite cold.

I will follow up this thread with an update after our next cold snap.

 

Are you sure the A/C part os off? During our recent mornings in the teens my Prius is nice and toastee after 15 min. drive to work. I have the combo defrost/floor button on temp. set to 70 and the A/c button off

 

Yes, I am quite certain the A/C is off, and I also have tried every possible setting.

Let's be clear, most any car can heat up OK with temperatures in the teens, I'm talking about -22F and colder, which is a real test of the heating systems.

 

we have temperatures in the teens here and I'm probably getting similar performance as you. It takes about 15 minutes to start getting some decent heat.

a/c has nothing to do with it. a/c just removes the moisture from the air.

 

-22 would find me with a one way ticket to the Carriabeen

 

My 2005 gets warm within about the first 2 miles of my 12 mile commute to work. By the time I DO get to work, I'm actually turning the thermostat down because it's a wee tad too hot.

 

It takes about 30 seconds before it comes on for me on a cold morning. I would say within 5 minutes it is warm enough to grow earthwarms

 

For folks with problems because of low temps (we rarely have low temps and almost never really low temps so I will never be an expert unless I move) how about a block heater. That might be a bridge to comfort. I do know of someone who put an electric blanket over her hood at night!

 

i can say without a doubt that i have never had a car defrost or start producing heat as quickly as my Prius.

i live near henry so cool is the operative word here but we did have a few days a while back with ice on the windows and by the time i did a quick once around on the side windows, the windshield was just about clear enough to drive away. all told, less than 2 minutes.

my other cars might have had a circle the size of a baseball in that time.

one thing i will say about when it was cold, there are vents that go straight to the back seats. i have often wondered if blocking them would increase the air flow to the front. (i dont like the high fan setting simply because its too loud) obviously i would like something that was easily removed for the occasional rear seat passenger.

 

Hey Dave, have you tried using the defrost/floor button? I noticed it makes the fan MUCH quieter even when it's on high.

 

As far as "accidently" running the A/C in cold weather, that should be impossible. The lubricant (PAG oil or similar) simply won't flow at those temps and you could ruin the compressor. Most automotive A/C systems prevent compressor engagement below 45 F.

The Bryant two speed Puron central A/C I have at the hobby farm also has a thermistor to prevent low temp operation, any temp below 55 F the A/C compressor is disabled.

If I park in heated parking, my heat is almost instant and quickly becomes hot. If I have to park outside, especially in temps below -18 C for a few hours, it can take +15 minutes of city driving before I feel comfy heat.

I had to get one of those cans of spray deicer just to keep the windows clear. Plugging in certainly helps, but not too many malls offer plug ins. Nor does street parking.

 

I disagree with Jayman on the statement that automotive a/c won't work below 45F, almost every system I'm familiar with works at any OAT. The compressor oil is absorbed into the refrigerant and circulated via movement of the refrigerant. In the 70's we spent more time in the spring recharging systems the weren't run during the winter and the seals leaked from non-use. Nowadays the a/c system is run anytime the vehicle is in defrost mode, unless the manufacture has installed a cancel feature.

 

Frank:

I'm not sure of the Prius, but the shop manual for my former 2000 GMC Sierra states the A/C compressor is disabled below 45 F. This is to protect the compressor from damage due to extended low ambient operation.

In my heated condo parking, I like to "exercise" the A/C once a week for about 3 mins. Otherwise, I'm not sure what you can do about seal problems, except most A/C made since R-134a have much improved seal design. Automotive A/C used in a place like Phoenix have short lives, so do A/C in Northern climates.

I'm familiar with industrial chillers and packaged HVAC, both regular piston and Scroll compressors, for computer rooms and control rooms. In a situation where you may need cooling year round (IBM S/390 comes to mind, along with "blade" servers and industrial control rooms), you must equip the exterior refrigerant compressor with a crankcase heater.

If you don't put a crankcase heater on the compressor, the manufacturer warns of dramatically decreased compressor life, and very catastrophic failure, especially in temps below +55 F compressor ambient.

Packaged HVAC and chiller makers such as Trane, York, and Carrier require the installation of the crankcase heater to maintain warranty if operated below 55 F outside ambient. Otherwise, the factory thermistor disables compressor run and sends an alarm.

Most modern chillers and packaged HVAC communicate via ControlNet, DeviceNet, or Industrial Ether. You get a screen pop like "Low Ambient Exceeded, Compressor Disabled."

 

the reason i dont use the auto air button to turn the fan on and off is because it will turn on the air conditioning at any temperature.

by hitting the defrost button twice, you can go into heat mode or toggle from heat to defrost without the air conditioning coming on.

however this method wont turn it off and that is the problem i have with it. i feel that the options we are afforded are not well chosen

 

air conditioning does not mean cold!

it means the air is conditioned by removing moisture!

setting the temperature makes it cold or hot not the a/c button!

a/c is always on by default because that's usually the best option.


As a side note, i want to mention that I originally stated that my heater does not get very hot. I want to take that back. With a few minutes the temperature now ramps up quite quickly.
I'm almost willing to bet that it was because the car was new and i had never used the heat in the car until now and maybe the system needed a little breakin (1-2 weeks) period before functioning optimally.

 

when the AC button lights up, that means the air conditioning is on. temperatures dont matter. the air conditioning still comes on.

 

I drove Camry yesterday while my Prius was getting the fuel-gauge/filler-pipe fix. I did not care much for the Camry overall. But that bigger engine put out some serious heat, and the manual controls were much nicer than our brain-damaged computerized controls. The Prius, with its little 1.5 L engine, needs a big electric heater for supplemental heat in sub-zero weather.