[nrvous]

Hi All,

Driving today with outside temp of 58 degrees in Normal mode:

Auto defog on
Max selected
Temp set to HI
Fan set to High
Recirc off


Car was driven for 15 minutes then used the settings above and driven in this setting for 10-15 minutes. Air out of the vents was ice cold the entire time.

I know we're dealing with electric heat here but I would have expected at least some type of warm air out of the vents.

Am I missing something or is it time for the dealer to troubleshoot?

Thanks!

 

[Barry]

Yes, you should have been too hot to stay in the car by then. Your electric heat is not working. Take it to the dealer. Meanwhile, if you need a workaround to get heat, drive in hold mode.

 

[somms]

I know we're dealing with electric heat here but I would have expected at least some type of warm air out of the vents.

Am I missing something or is it time for the dealer to troubleshoot?

Thanks!

You could check the fuse. Otherwise as Barry commented it would be up to the GM service dept to fix...

 

[lagagnon]

Instead of setting fan to High set Auto ON and let it choose the fan speed to properly detect temperature. Try that....

 

[nrvous]

Yes, you should have been too hot to stay in the car by then. Your electric heat is not working. Take it to the dealer. Meanwhile, if you need a workaround to get heat, drive in hold mode.

Thanks Barry. Just for comparison, I tried similar settings in my wife's new Leaf and it fried me in like 5 min. Time to go to the dealer...

 

[jcanoe]

There is obviously a problem with your Volt's HVAC and/or electric heating. If you select the Classic Enhanced energy display on the Driver Information Center you will be able to see the total kWh being used by the Volt at any time. For example:

Volt powered on, no HVAC: 0.5kWh (the Volt is just operating in the EV equivalent of idling)
AC on Economy: 0.5 - 3kWh
AC on Max: 0.5 - 6kWh
HVAC set to Economy, thermostat set for heat (set to >71F when the outside temperature is ~63F): up to 6kWh)
HVAC set to Maximum, thermostat set to Hi: up to 7-9kWh *

* You will feel warm air blowing from the vents almost immediately. You will have to turn the heat down/off within a few minutes as the Volt will become uncomfortably warm (even when the outside temperature is below 20F.)

Other than the electric blower fan there is no 12V fuse that you can access that controls the electric heating element. The electric heating element is powered by the high voltage battery and can draw up to 9kW.

 

[nrvous]

For what I paid for this car I think I'll have the dealer check out the fuse and if it's blown then why it's blown! But thank you for the suggestion which makes sense - there was a time when I would have considered taking a look but that day has passed!

 

[nrvous]

There is obviously a problem with your Volt's HVAC and/or electric heating. If you select the Classic Enhanced energy display on the Driver Information Center you will be able to see the total kWh being used by the Volt at any time. For example:

Volt powered on, no HVAC: 0.5kWh (the Volt is just operating in the EV equivalent of idling)
AC on Economy: 0.5 - 3kWh
AC on Max: 0.5 - 6kWh
HVAC set to Economy, thermostat set for heat (set to >71F when the outside temperature is ~63F): up to 6kWh)
HVAC set to Maximum, thermostat set to Hi: up to 7-9kWh *

* You will feel warm air blowing from the vents almost immediately. You will have to turn the heat down/off within a few minutes as the Volt will become uncomfortably warm (even when the outside temperature is below 20F.)

Other than the electric blower fan there is no 12V fuse that you can access that controls the electric heating element. The electric heating element is powered by the high voltage battery and can draw up to 9kW.

Thanks! I didn't even think to look at the power being used. Excellent idea and will have a look at that on the drive home.

 

[nrvous]

There is obviously a problem with your Volt's HVAC and/or electric heating. If you select the Classic Enhanced energy display on the Driver Information Center you will be able to see the total kWh being used by the Volt at any time. For example:

Volt powered on, no HVAC: 0.5kWh (the Volt is just operating in the EV equivalent of idling)
AC on Economy: 0.5 - 3kWh
AC on Max: 0.5 - 6kWh
HVAC set to Economy, thermostat set for heat (set to >71F when the outside temperature is ~63F): up to 6kWh)
HVAC set to Maximum, thermostat set to Hi: up to 7-9kWh *

* You will feel warm air blowing from the vents almost immediately. You will have to turn the heat down/off within a few minutes as the Volt will become uncomfortably warm (even when the outside temperature is below 20F.)

Other than the electric blower fan there is no 12V fuse that you can access that controls the electric heating element. The electric heating element is powered by the high voltage battery and can draw up to 9kW.

Just a quick update on this. I tried running the car in Hold mode for about 10 minutes on the way home and there was no difference in the temperature of the air coming out of the vents. I also checked the amount of kW used when electric heat was on or off and could only see a difference of about 1kW if that while the car was stopped.

One other slightly odd thing is that I heard some clicks/clunks from the dash under braking while the electric heat was on. If I shut the HVAC off, no more clunks. Never noticed it before until today. Really odd.

Service appointment at dealer scheduled for Friday. I'll be getting the brake recall done that day as well. I'll let you all know how it goes.

 

[jcanoe]

10 minutes on the highway should have been long enough to heat up the engine coolant to 160F, below that temperature the Volt will use the electric heating element. If you were in local driving every time you stop the engine may shut off making it take longer to reach the 160F needed for the engine coolant valve to open and circulate in the cabin heat exchanger. You can display the engine coolant in the Driver Information Console by using the up down arrows on the right side of the steering wheel.

In any event, any time you set the HVAC to Automatic, Maximum and the cabin temperature control to Hi you will see at least 7 or 8 kW being pulled from the battery to provide power for the electric heating element, until the coolant circulating inside this cabin heat exchange loop reaches the required temperature. You should have been blasted with very warm air inside of a minute.

 

[nrvous]

10 minutes on the highway should have been long enough to heat up the engine coolant to 160F, below that temperature the Volt will use the electric heating element. If you were in local driving every time you stop the engine may shut off making it take longer to reach the 160F needed for the engine coolant valve to open and circulate in the cabin heat exchanger. You can display the engine coolant in the Driver Information Console by using the up down arrows on the right side of the steering wheel.

In any event, any time you set the HVAC to Automatic, Maximum and the cabin temperature control to Hi you will see at least 7 or 8 kW being pulled from the battery to provide power for the electric heating element, until the coolant circulating inside this cabin heat exchange loop reaches the required temperature. You should have been blasted with very warm air inside of a minute.

Thanks! I should have thought to have a look at the coolant temp. I'll try again tomorrow and keep an eye on it. Something is definitely not right. I'm getting a loaner on Friday so that is nice! Thanks again.

 

[Barry]

I would not be in a hurry to do any more experimenting with the engine running in Hold mode. Since you didn't get any heat in Hold mode the last time, it may be possible that your water pump is not working. You don't want to overheat your engine. At this point I would just turn it over to the dealer.

 

[nrvous]

I would not be in a hurry to do any more experimenting with the engine running in Hold mode. Since you didn't get any heat in Hold mode the last time, it may be possible that your water pump is not working. You don't want to overheat your engine. At this point I would just turn it over to the dealer.

Yikes, good advice! Sure hope that's not the case and certainly would expect some sort of temp warning or error message if the water pump failed or is failing. Took the car on a long trip in 90+ temps a couple of weeks ago and Hold mode worked flawlessly as did the AC.

No heat again this morning. Coolant temp reached about 180 in Hold mode. Never got any heat.

 

[jcanoe]

180F coolant temperature in Hold mode after a period of perhaps 10 minutes driving is perfectly normal. In my 2017 Volt the engine coolant temperature will typically reach equilibrium at between 185 - 205F.


If your coolant pump was malfunctioning there should be a corresponding error code. It is probably a stuck control valve inside the cabin heat exchanger.

 

[Barry]

Yikes, good advice! Sure hope that's not the case and certainly would expect some sort of temp warning or error message if the water pump failed or is failing. Took the car on a long trip in 90+ temps a couple of weeks ago and Hold mode worked flawlessly as did the AC.

No heat again this morning. Coolant temp reached about 180 in Hold mode. Never got any heat.

If your coolant temp is stabilizing at that level, then no worries about the pump being bad. I am sure you would get a warning, but I assume it might occur after exceeding the normal temperature range, and also you may not notice it right away, so I was just thinking there is no reason to put the engine through that.

 

[JRRF]

I can't remember the exact circumstances, but I seem to remember that my first fall with the Volt I also wondered why I wasn't getting any heat. It became obvious there was heat when it really got cold out. I hope that's all it is.

If your water pump or radiator system had a problem you would never have gotten this far in the summer. So it's likely something less serious.

 

[Barry]

The heating circuit is more complicated than in a typical car. The way I understand it, there are 2 coolant loops involved. One to cool the engine and one to heat the cabin. The cabin loop has its own separate pump, an electric heating element, and some valves that can either isolate it from or join it to the engine loop. And of course this is all controlled by a computer with sensors and actuators. So there are a lot of things that could go wrong. And heating problems are not uncommon with the Volt.

 

[nrvous]

Thanks everyone. It will be interesting to see what the dealer finds. We'll see how it goes and I'll keep you all posted. Thanks again for all the advice!

 

[obermd]

The clunks you heard indicate the ducting redirection mechanism and gears aren't working properly. To fix this the dealership will have to take the dash completely out of the car to replace the main HVAC duct box. Expect a two to four day service call on this.

 

[nrvous]

The clunks you heard indicate the ducting redirection mechanism and gears aren't working properly. To fix this the dealership will have to take the dash completely out of the car to replace the main HVAC duct box. Expect a two to four day service call on this.

I hope the loaner is a Vette