Can I stop paying rent until my landlord fixes things?Beta*

It's risky and usually not advised. Withholding rent puts you into arrears, and arrears are a reason the landlord can use to evict you. Rent arrears of three months is a ground for eviction the court must grant. Safer routes are to report the problem in writing, involve the council's environmental health team, and claim compensation or a rent reduction for the disrepair. There is also a legal process for paying for a repair yourself and deducting the cost from the rent, but it has strict steps. Get advice before you try it.

Sources: Shelter: withholding rent for repairs