Partner rough cold starts

Sounds familiar! I've got a Partner too. A while back, I had similar symptoms – poor running when it turned cold, and the MPG took a hit. I also found an error code related to the auxiliary heater – pretty sure it's part of the PTC (Positive Temperature Coefficient) heater system, which is there to help warm up the cabin and the engine coolant faster on cold days. Did you check the fuse?

Interesting! I know what a PTC heater is, but I didn't know it would affect the engine so much. Where is the fuse located, and how can I check the heater is working? I'm trying to avoid the workshop, can't afford expensive repairs right now...

I wouldn't try to fix it yourself. The fuse is usually in the fuse box under the dashboard, but honestly, chasing electrical faults without the right tools can be a nightmare. From my experience, if the PTC heater itself is faulty, it's usually best left to the professionals. They can properly diagnose it and replace it. My local garage charged me 350€ for the entire repair of the HVAC system, including parts and labor.

Thanks for the advice! I was hoping to avoid it, but it sounds like a workshop visit is unavoidable. I'll book it in and mention the PTC heater specifically. Hopefully, it's a straightforward fix and that is all that is wrong with the temperature control. Wish me luck!