Astra poor cold starts higher fuel consumption

I had similar cold air issues in my Astra diesel, and shocking fuel consumption too. Is your HVAC system playing up? Could be an electrical fault, like you said.

HVAC is normal, but I'm still getting cold air and higher fuel consumption. What was the cause and solution for your Astra?

Sounds like the same gremlin! It was a defective PTC heater. The workshop diagnosed it right away and it cost around 350€ to replace. Get it checked out. I bet you have the same problem!

Thanks for confirming my suspicions and sharing your experience! I'll get the PTC heater checked ASAP. Hopefully, that'll fix it!