Will a 2nd degree burn heal if the blister is not popped?

Second degree burns: Are healing under the blister. The blister has to rupture some day but if its over a week from the burn, its likely your skin is already healed.

Protect it: An unpopped blister represents a closed sterile environment. Yes on occasion one can become infected then it is time to open it, however the risk of infection in a dressed open wound is still higher than that of an intact blister. The blister will gradually resolve with time i wouldnt use an ointment on blisters at all.