the type I was flying was a c152, temp was about 32 celsius. Engine didn't complain at all on finals, but I had it idle for some time on approach. I'd had carb heat hot immediately prior to making my base turn and stayed that way until established on finals @ 60KTS with a nose down attitude pointing at the numbers
Hmmm..... I hesitate to say too much, or this thread will turn into yet another discussion of carb icing. And if you ask ten pilots about use of carb heat, you'll probably get eleven opinions at least. However, basically you can get carb ice in almost any weather conditions in the UK, and almost any power setting. But you are MOST likely to get it at low power settings, ie on base and final. So you apply carb heat at that time. Now, some pilots and instructors, in some aircraft, reckon you should then leave it on till you land, while some recommend putting it in on short final. But the ONLY reason for putting it to cold again is so that you have full power if needed for a go-around. And you could still get carb ice on final, so you want to leave putting it off till pretty late...maybe the last 200 ft or so.
I'm not questioning the way you've been taught. It's just that there's no substitute for knowledge in the flying game. Read and understand a bit about carb icing...and everything else. I know, too much to do, isn't there.
For the record, the second or third time I flew a C150, with way more flying hours than you've got, I had to wait in a queue before taxying. At some point when doing this, the engine died. I taxied back, went into the flying school, and loudly and vociferously complained that there was something wrong with their aircraft. An instructor told me it was carb ice. It can't be, said knowall little me, it's too cold and dry, and I hadn't been waiting that long, and it's never happened before. So he took me out and showed me the differences between the engines on a C150 and C152, and why the C150 was so likely to get carb ice at any time. And yes, I felt like a prat. But I learned something that day.
Sorry to have called you a prat.
I was simply trying to make the point - maybe too strongly - that you should stop worrying, and instead look at what a good learning experience you'd had...far more so than if you'd just flown a few circuits.