"30a is way too much for either use. Take this opportunity to buy a
pair of
15a (or whatever) breakers and get rid of the double 30a.
Might fix your problem, might not; but necessary either way. "

Before he seperates a double breaker, he better be sure how it's wired,
which he obviously doesn't understand. It's possible and even likely
that each leg of the double breaker are run together into the same box
somewhere. Seperating the breakers would allow someone later
attempting a repair to turn off one breaker and not realize the other
wire is still hot, creating a dangerous situation.