How Long can you wait to file

I am in a dispute with a plumer in New Jersey. In august he did some work for me as I needed to have my heater certified.When done his final bill in my opinion was very labor inflated.I wrote a letter detailing the differances in labor Hr's and sent a check for the new amount.This was in August and I have neither heard from the plumber or has he cashed my check.I am assuming he intend's to take me to small claim's court.Is their a limit to how long he can wait.
Help Fred

This depends a lot on what agreement you had with the plumber. For example, New Jersey has the following Statute of Limitations (in years):
Open Acct.: 6
Sale of Goods: 4
Written Contract: 6