I have a 2nd degree burn. it was red and blistered but now it is peeling and not painful. is this a good sign it's healing?

Probably: 2nd-degree burns will heal on their own in 1-3 weeks, given good wound care & good nutrition. They are initially red, painful, and possibly covered with blisters. As they heal, they dry up, the blisters slough off, and the pain disappears.

Could be...: Typically pain going away is a sign of healing. Redness , swelling and drainage should be going away as well.