Peugeot 301 Auxiliary Heater Problems

I had similar issues with my 301. Not sure what engine you have but check your glow plugs. If it is the glow plug, that might be the culprit.

Glow plugs, eh? Interesting. Where are those located exactly? Is it a tough job?

Yeah, that's what it was for me. Honestly, it's a pain to get to without the right tools. I'd suggest getting it checked out at a workshop, they'll be able to diagnose it properly.

Cheers, took your advice and glow plug was indeed the issue! Cost me 440€ to get it sorted but at least it's done.