Good post by Chad Storm, so I'll add in more points / elaboration.
Defects in Flat
If you think you can live with a minor defect (eg wardrobe drawer cannot close properly, etc), and not report, it, don't. This is not like the SAF. At the end of your contract (presumably by the end of your school year), you will be asked to fix it, even if it was like that initially.
Radiator problems
This is variable based on University, but if you have an orientation week which is optional, your radiator may not be switched on, or rather, you can turn it on, but no heat will be emitted. Nothing much you can do about this. Unless your 'rent' is part of any orientation fees you are paying, you can only lan lan suck thumb. But if your 'rent' is part of your orientation fees, you can make a fuss, and they'll probably give you extra blankets for the night.
Body Acclimatization
Unless you've been overseas in appropriate countries, expect to feel cold for the first few nights. Daytime is still OK. Wear several jackets / buy a duvet, until the temperature doesn't bother you. When I first flew over, it was about 14 degrees at night, and was freezing. This year, I came back early, stayed at a friend's place with the radiator not working, and managed to sleep without a blanket. So you will still be acclimatized even after flying back to SG.
Medical Treatment
Is not free. Consultation is free. Unless you are very lucky to be at a University where they subsidize medicine, you will be given a form, and asked to go to the pharmacist to get the required medicine.
Racism
It exists everywhere, but it shouldn't affect you, for the main reason words like "Chink" isn't even heard in SG. At most you'll be like WTF? And no one here calls people "ah neh" or whatever... But you may get people going up to you (if you are Chinese) and say: "Konichiwa".
More pressing problem is that you'll paradoxically get people saying:
"Gosh, you speak good English for an international student"
and the same person mocking you for Singlish.
On the plus side, while British students will look very severely on "Did you cut your hair?" "No, I got my hair cut by a barber", or "On the light", and British people may comment on you speaking too fast, your vocabulary will be better than them.
On the language issue, you might even get the smarter British students asking you whether: "chee bye" is Mandarin for rain, and "chao chee bye" is Mandarin for heavy rain.