how do I withhold rent due to ignoring apt repaits

send a certified letter to landlord: identifying the escrow account (separate account, suggest a credit union) you are putting the rent into the estimated cost of the repair the number of times you have contacted them about the issue and their response advise you will negotiate on how much rent to pay the rent once the repair is done   cautions- landlords will treat this as a declaration of war they will probably NOT renew your lease after this   good luck