I probably wouldn't put the plant near the radiator, instead try putting it in a place that gets a breeze, like near a window.
Once the soil has dried out for the first inch or two, make sure that when you are watering the plant, the excess water is allowed to drain away.
You can also scoop the mold off the soil with a spoon, though try not to breathe any in. This probably won't stop it from growing back though and is more of a temporary fix.
I really hope this helps. Looking forward to hearing your results.