Hi!

It has snowed heavily in my area and weather has been super cold (like 5 degree F at night). This morning, I removed the snow and started the car, put the AC on highest heat to get rid of the ice on the windshield. I noticed that the AC vents were not blowing warm air for a long long time. I was basically just sitting in the car with car on idle. I must have sat there for like 10-15 minutes, and I didn't have warm air.
I cleared the ice with different means and then started driving. The air was warm after maybe 10-15 minutes of driving. It still wasn't as warm as I would have expected it to be. Seems like engine needs to warm for AC to be warm enough?

I have not experienced this with any car before. Usually, the air out of vents is warm pretty quickly. I also don't remember it being this bad with my car before. I have had the GLB for 4 years now. But maybe I just didn't notice it or it has been this cold after a long time.

Is what I am seeing normal? What could be the issue? If this is normal, how do you deal with it in super cold weather? Let me know if you have any thoughts. One data point of note might be that I recently got my car serviced and had told them that the AC was too loud. They did something to make it less noisy. I really hate going to the service center (very busy with young family, messes with my schedule). If there is something quick I can do myself, I would love to try that.

Thanks!

Our GLB & GLA don’t warm up nearly as quickly as our C250 did. But at 17F here, I had enough warm air to melt about ½ inch of frozen rain on the windshield in maybe 4-5 minutes. Try taking it off AUTO and selecting the vents in the menu. Also make sure that one of the temp settings is not on LOW.

I noticed the same thing with my 2023 GLB I got 3 months ago. It's not the same as my '08 Lexus ES 350 that warms quickly.

When you set it to Auto make sure to turn off the A/C. I've noticed the A/C button light is on automatically which you have to turn off to get warm air hitting the windshield.

I had my A/C blower serviced just recently to remove leaves in the fan that was making it extremely noisy at high fan speeds. This should not affect the amount of time it takes to heat up your vehicle but again make sure the a/c does not come on automatically.

Oh wow, okay. I will try that. "I had my A/C blower serviced just recently to remove leaves in the fan that was making it extremely noisy at high fan speeds." -> I had the exact same thing done! The AC makes a real loud noise at higher fan speeds.

Thank you! It was off auto when I tried and none of the temp settings were on low. However, i will try the recommendation in another post to just turn off the AC itself.

5-10 min delay for the car to start blowing hot air is not unusual given single digit temperatures you are experiencing.
Heat comes from the engine and your fan and dampers will not open until engine and coolant is sufficiently warm to circulate it through heat exchanger coil in the cabin.

Does anyone know why the a/c turns on auto when you try to heat up the car? I've experienced this my GLB and loaners as well the electrical version.

A/C helps keep the interior windows from fogging. If the outside temperature is below a certain point (35F maybe?) it doesn’t run even if the switch is on.