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Discussion Starter #1 (Edited)
Hi all,

Here in the mid-Atlantic, the temps went from about 70-80 on average over the past month down to the high 40s-low 50s these past few days.

Having bought my car in May, this has really been the first time I've felt the need to use anything more than the seat heaters.

When I set the temp to 70 and put it on auto, eco mode, the vents put out cold air. The drive was about 30 minutes, but it did not warm up at all on the ride home. In contrast, my home heat set to 67 was producing heat you could actually feel coming out of the vents.

The outdoor temp was 48 at the time, so the interior temperature was likely similar. The car had sat empty for 3 hours in a parking lot prior to the drive. I understand that car heating systems, and particularly the Volt's work differently, but I really got no heat at all.

This is not really an issue for me in the fall weather, but my wife really likes having tangible amounts of heat come out of the vents, and I can't blame her. If this is something broken, I'd like to get it fixed before temps drop into the 30s.

Is this fairly standard behavior for eco mode? Do I need to put it on MAX to get any sort of heat you can actually feel out of the vents? Does it just take 40+ minutes to heat up? Or is this a sign that something is broken in the heating system?

Any and all input appreciated.
 

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Hi all,

Here in the mid-Atlantic, the temps went from about 70-80 on average over the past month down to the high 40s-low 50s these past few days.

Having bought my car in May, this has really been the first time I've felt the need to use anything more than the seat heaters.

When I set the temp to 70 and put it on auto, eco mode, the vents put out cold air. The drive was about 30 minutes, but it did not warm up at all on the ride home. In contrast, my home heat set to 67 was producing heat you could actually feel coming out of the vents.

The outdoor temp was 48 at the time, so the interior temperature was likely similar. The car had sat empty for 3 hours in a parking lot prior to the drive. I understand that car heating systems, and particularly the Volt's work differently, but I really got no heat at all.

This is not really an issue for me in the fall weather, but my wife really likes having tangible amounts of heat come out of the vents, and I can't blame her. If this is something broken, I'd like to get it fixed before temps drop into the 30s.

Is this fairly standard behavior for eco mode? Do I need to put it on MAX to get any sort of heat you can actually feel out of the vents? Does it just take 40+ minutes to heat up? Or is this a sign that something is broken in the heating system?

Any and all input appreciated.
You did not state the year of manufacture of your Volt. Gen 1 Volts and Gen 2 Volts have different climate controls. There is probably nothing wrong with your Volt's HVAC system. When you selected Eco the Volt will expend as little energy as possible to enable the cabin to reach the set temperature even if it takes longer than your anticipated trip. The best way to stay comfortable in a Volt in winter is to precondition the cabin while the Volt is still plugged in. Set the temperature to at least 73F and set to Max. Set the airflow to recirculate unless the humidity level is high (if it is raining, sleeting or snowing) as this can cause the windshield to fog. Check that the auto defogger setting is On.

GM has provided 5 ways to stay warm in your Volt so learn to use them to your advantage.

1) heated front seats, optional heated rear seats and heated steering wheel. These accessories use the 12V electrical system, consume only a couple of hundred watts of power (at most.) Use these liberally to help stay warm in the Volt's cabin.

2) Precondition the cabin before your start driving. This is best done while your Volt is still plugged in, preferably using Level 2 charging but you can also precondition when charging at Level 1. The standard preconditioning cycle runs for 10 minutes, 20 minutes total if you extend the preconditioning cycle or run a second preconditioning cycle. After two cycles you must start the Volt manually, no further preconditioning can be enabled. Preconditioning can also start the Volt's internal combustion engine (ICE) to help warm the cabin. You can set Engine Assist Heat Plugged In to be "No." If you park inside a garage be sure to set the Engine Assist Heat Plugged in to "No."

3) Electric heat: This can consume significant amount of power (up to 9kW in the Gen 2 Volt) but if the coolant in the cabin heat exchanger is already prewarmed from preconditioning it does not use nearly as much power if you select a reasonable temperature setting such as 73F and set to Eco and recirculate. In very cold weather, to maximize the electric heat, deselect Auto and set the HVAC to a medium high fan speed with the air directed at the floor and/or windshield, set to Max, airflow to recirculate, set temperature to 82F or higher (you will need to lower this after a few minutes as you will likely feel the effect of too much heat.)

4) Engine Assist Heat: The Volt will start the gas engine to generate heat for the cabin when the outside temperature reaches 35F or colder. In the Gen 2 Volt 2016 - 2018 you can defer Engine Assist Heat until the temperature is at or below 15F. In the 2019 Volt you can defer Engine Assist Heat until the temperature drops to -14F (this is not something you would likely experience in the mid-Atlantic area.) The driver information console will briefly display the message 'Engine Running Due to Temperature (ERDTT.) Engine Assist Heat works well, uses just a little gas to generate heat for the passenger cabin. Unlike the other modes where the ICE runs, if ERDTT is active the gas engine will not shut off at traffic signals, the gas engine will continue to run until the engine coolant reaches at least 150F, then run as needed to maintain the engine coolant between 120F -140F.

5) Engine heat while using the Volt's internal combustion engine (ICE), the Volt will automatically shut off the electric heat and switch to using engine heat once the engine coolant has reached ~150F - 160F (takes about 5 miles of driving for the engine to warm the coolant to at least 160F.) The waste heat from the ICE will warm the passenger cabin as in any other vehicle with an ICE.
 

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Discussion Starter #3
Thanks, jcanoe. I posted in the Gen 2 forum, so thought it was a given, but understand that's not always the case.

It's a 2017 Volt. Regarding preconditioning, I unfortunately bought my car after OnStar decided they were giving 3 months complimentary access to remote preconditioning rather than the former 5 years, and I can't justify an extra $15 a month for this feature. Is there anyway to set this up without leaving the key fob in the vehicle and manually setting the climate settings?
 

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If you're cold at 70, turn the knob up to 75 or 80. The car doesn't have any way of knowing what is going on in your head, you have to tell it.
 

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Thanks, jcanoe. I posted in the Gen 2 forum, so thought it was a given, but understand that's not always the case.

It's a 2017 Volt. Regarding preconditioning, I unfortunately bought my car after OnStar decided they were giving 3 months complimentary access to remote preconditioning rather than the former 5 years, and I can't justify an extra $15 a month for this feature. Is there anyway to set this up without leaving the key fob in the vehicle and manually setting the climate settings?
Unfortunately you must use the MyChevrolet App or the key fob to initiate the 10 minute preconditioning cycle. (You can also initiate the preconditioning cycle from an Apple Watch but this requires an iPhone and the MyChevrolet App on the iPhone and Apple Watch as well.) You can precondition using the key fob, preconditioning can be initiated if the Volt is parked within range of the key fob. Press the button to lock the doors, then immediately press and hold the button with the revolving arrow for 3 seconds. The Volt's exterior parking lights should come on and the HVAC system will heat or cool the Volt depending on the temperature setting. To extend the preconditioning cycle for an additional 10 minutes, you must wait 30 seconds after initiating the preconditioning cycle and repeat the key fob button sequence a second time.
 

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Discussion Starter #6
If you're cold at 70, turn the knob up to 75 or 80. The car doesn't have any way of knowing what is going on in your head, you have to tell it.
I wasn't cold. It was 48 degrees outside, and therefore, likely approximately that temperature inside the car when we got in after the car had been off for three hours. On our 30 minute drive, with the temp set to 70, eco, auto, the vents produced air that was colder than the ambient air temperature in the car. This would not seem to be an efficient or effective way to bring the cabin temperature up to 70 degrees, which is, as I understand it, the purpose of automatic climate control.
 

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I wasn't cold. It was 48 degrees outside, and therefore, likely approximately that temperature inside the car when we got in after the car had been off for three hours. On our 30 minute drive, with the temp set to 70, eco, auto, the vents produced air that was colder than the ambient air temperature in the car. This would not seem to be an efficient or effective way to bring the cabin temperature up to 70 degrees, which is, as I understand it, the purpose of automatic climate control.
Set the cabin thermostat control to at least 73F, the air from the vents will feel a bit warm. If you feel cold air at the vents, be aware that the Volt can run the AC at any time to lower the humidity in the cabin to prevent the windshield from fogging. If this is a problem you can turn off the Auto Defog setting but with two passengers the windshield is likely to start fogging up without additional cabin heat directed at the windshield or the AC to lower the humidity. If you turn off the cabin air recirculate setting this can help reduce windshield fogging. Of the two ways to prevent the windshield from fogging, the AC uses less energy than the electric cabin heat. You can also try one of the window treatment products that reduces fogging on the inside of the windshield (I have no experience with these windshield treatments.)
 

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I wasn't cold. It was 48 degrees outside, and therefore, likely approximately that temperature inside the car when we got in after the car had been off for three hours. On our 30 minute drive, with the temp set to 70, eco, auto, the vents produced air that was colder than the ambient air temperature in the car. This would not seem to be an efficient or effective way to bring the cabin temperature up to 70 degrees, which is, as I understand it, the purpose of automatic climate control.
I find that when the difference between the outside temp and the temp you set is small, the heating is quite ineffective. 70 vs 48 seems like a big difference, but I'm not surprised you barely felt any heat in eco mode. If it were 20 degrees outside, you would have noticed it.

Try setting the heat to 74 or higher in eco mode and see if that helps. You could also use Max mode, which should give more power the electric heater and turn the fans up higher to try to warm up the cabin as fast as possible. If either of these doesn't work, there's a problem that the dealer should look at.

Finally, if you set auto-defog to On, the a/c may come on even though it seems like it shouldn't (i.e., the windows aren't threatening to fog). I find this EXTREMELY annoying because it produces exactly the behavior you describe - colder air blowing into the cabin than the cabin air. That's why I disabled auto-defog (there's a setting).
 

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Plenty of people have experienced the same thing their first winter with a Volt. The problem is eco mode. In that mode the electric heating element comes on (you can see that in your economy score), but only slightly, and the fan will stay fairly low as well. Unlike other car's auto-climate control, eco mode does not try to do anything specific other than ensure your car doesn't get hotter than the temp you selected. Conversely, if you use the max setting the system will actually try to reach the set temperature like you are familiar with from other cars.
 

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Thanks all for the detailed feedback! This is what I was hoping to learn from this question.
My subjective experience /opinion, based on two winters with my 2017 Volt, is that when it comes to preconditioning using the MyChevrolet App; to quote the Rolling Stones, "you can't always get what you want, you get what you need. The App will precondition the cabin but will ultimately select the temperature and climate control settings to do so. When you use the key fob to precondition the Volt, this always uses the last HVAC settings you set in the cabin. In winter I always set the HVAC controls for Auto, Max, Recirculate, Temperature = 80F and up to Hi before powering off the Volt. The Volt will use these settings the next time I precondition using the key fob. With the App I get the feeling that the App does what is most efficient, as far as preconditioning, regardless of the cabin HVAC settings.
 

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Discussion Starter #12
This is obviously a fairly minimal issue and one I could learn with experience rather than ask you, but when you say that the Volt will remember the last climate settings used when you precondition with the key fob, does that include the heated seats?
 

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This is obviously a fairly minimal issue and one I could learn with experience rather than ask you, but when you say that the Volt will remember the last climate settings used when you precondition with the key fob, does that include the heated seats?
The heated seats (front seats only) can be set to come on automatically depending on the air temperature outside of the Volt's cabin. If set to auto, depending on the temperature, the heated front seats can come on during preconditioning. When set to automatic the Volt's heated seats will dynamically select low, medium or high heat levels. In the 2018 and newer Volt, if the Volt has the optional heated steering wheel, the steering wheel heater can automatically come on during preconditioning.
 

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Discussion Starter #14
The heated seats (front seats only) can be set to come on automatically depending on the air temperature outside of the Volt's cabin. If set to auto, depending on the temperature, the heated front seats can come on during preconditioning. When set to automatic the Volt's heated seats will dynamically select low, medium or high heat levels. In the 2018 and newer Volt, if the Volt has the optional heated steering wheel, the steering wheel heater can automatically come on during preconditioning.
Gotcha -- Thank you!

FYI, my 2017 also has the heated steering wheel. It's a Premier, has park assist, proximity sensors, but doesn't have DC1, DC2, or ACC. From what I've seen, it's a bit of an odd duck.
 

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Hi all,

Here in the mid-Atlantic, the temps went from about 70-80 on average over the past month down to the high 40s-low 50s these past few days.

Having bought my car in May, this has really been the first time I've felt the need to use anything more than the seat heaters.

When I set the temp to 70 and put it on auto, eco mode, the vents put out cold air. The drive was about 30 minutes, but it did not warm up at all on the ride home. In contrast, my home heat set to 67 was producing heat you could actually feel coming out of the vents.

The outdoor temp was 48 at the time, so the interior temperature was likely similar. The car had sat empty for 3 hours in a parking lot prior to the drive. I understand that car heating systems, and particularly the Volt's work differently, but I really got no heat at all.

This is not really an issue for me in the fall weather, but my wife really likes having tangible amounts of heat come out of the vents, and I can't blame her. If this is something broken, I'd like to get it fixed before temps drop into the 30s.

Is this fairly standard behavior for eco mode? Do I need to put it on MAX to get any sort of heat you can actually feel out of the vents? Does it just take 40+ minutes to heat up? Or is this a sign that something is broken in the heating system?

Any and all input appreciated.
70 doesn't cut it for mine either. It has been in mid-low 50s outside here. I needed to increase it to 80 to 85 to feel the warm air.
 

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Always remember you are Captain of the ship. The car has some smarts, but compared to your intellect, it is a moron. Show your authority, don't take any back talk! If you want heat, turn that knob until you get some. Insubordination should not be tolerated!
 

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I don't understand why it needs 9KW for electric heating. I can heat my bathroom in a couple mins with a 1KW space heater
9kW is the maximum power used by the Gen 2 Volt's electric heater unit but typically when active the electric heater uses up to 6kW or 7kW. Once the cabin heat exchanger coolant has reached sufficient temperature to heat the cabin the electric heater cycles on and off to maintain the set cabin temperature. That is why it is so beneficial to precondition the Volt while still plugged in, charging. Most of the energy needed to pre-warm the coolant and the cabin can be replenished (if charging using Level 2) during tthe 10 minute preconditioning cycle. Typically, using Level 2 charging, my Volt displays a 0.6 - 0.8 kWh battery SOC deficit following the end of the preconditioning cycle. This is perhaps 2-3 miles of EV range, a fair trade off for starting off in a warm cabin. Depending on the outside temperature the Volt's cabin stays warm for ~15 minutes. Then you can decide if you want to pulse the electric heat or just rely on the seat heaters and steering wheel heater (if equipped) to stay reasonably warm for the remainder of the drive.
 

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Hi all,

Here in the mid-Atlantic, the temps went from about 70-80 on average over the past month down to the high 40s-low 50s these past few days.

Having bought my car in May, this has really been the first time I've felt the need to use anything more than the seat heaters.

When I set the temp to 70 and put it on auto, eco mode, the vents put out cold air. The drive was about 30 minutes, but it did not warm up at all on the ride home. In contrast, my home heat set to 67 was producing heat you could actually feel coming out of the vents.

The outdoor temp was 48 at the time, so the interior temperature was likely similar. The car had sat empty for 3 hours in a parking lot prior to the drive. I understand that car heating systems, and particularly the Volt's work differently, but I really got no heat at all.

This is not really an issue for me in the fall weather, but my wife really likes having tangible amounts of heat come out of the vents, and I can't blame her. If this is something broken, I'd like to get it fixed before temps drop into the 30s.

Is this fairly standard behavior for eco mode? Do I need to put it on MAX to get any sort of heat you can actually feel out of the vents? Does it just take 40+ minutes to heat up? Or is this a sign that something is broken in the heating system?

Any and all input appreciated.
Hi,

FWIW, I had very similar issues to what you describe with my 2018 Volt. I could not get the car to generate cabin heat in either ICE or EV modes. No climate or touchscreen setting combination provided heat even though outside air temps were in the hi 40s/low 50s.

I took the car in and they diagnosed the issue. Here is a quick summary:

A problem was found with the under hood fuse block wiring to the auxiliary coolant pump. The auxiliary pump moves coolant to the heater core for cabin heat. The termination point for the pump within the fuse block was faulty which in turn prevented the pump from receiving power. The fuse block was replaced which solved the problem. I am happy to report the car now has tons of heat and defogs great!
 
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