Legal Question in Real Estate Law in California

Until escrow closes, the seller remains the owner with the same responsibilities as any owner. Whether a repair is something that must be done before escrow closes depends in large part as to what the intent and promises of the parties were. If the buyer knew before escrow opened that the water heater was leaking but did not require it be repaired, then the seller might not have to fix it.

If by "active repairs" you mean the old owner -- who is still the owner during escrow -- contracted for them and they were under way, then yes, for sure the old owner is responsible for the cost.