The production overhead account gathers allofthe production overheads (or indirect costs) in a period.

E.g.

At the end of the period the production overhead cost is absorbed into work in progress costs using the predetermined overhead absorption rate. 

The amount absorbed is credited in the production overhead account and debited in the work in progress account.

In the above, if we assume $24,000 would be debited to the work in progress account, the balance on the production overhead account would be zero.

Where there is a remaining balance on theproduction overhead account, this represents the amount of production overhead which is under absorbed (debit balance) or over absorbed (credit balance).