Replace it, the heater isn’t gpoing to last much longer either. You’ve got 12 years of use out of them both, which isn’t bad, not great, but not bad either. THe both of them will nickle and dime you to death as time progresses.
Man, central AC units are expected to last 25-30 years around here. Dry area, though. And the furnace unit (including elements) in this house lasted 25 years until replaced. Our heat pump is 11 years old and I consider it brand new.