To ask your advice?

[FriendlyFiyahsss]

My niece lives in a houseshare: there are 4 of them paying c£2500 a month to live there.

Great landlords but over the past couple of weeks, things have broken down eg faulty kitchen lights, broken washing machine for two plus weeks, leaking roof in bathroom and radiator not working in one bedroom.

Is it fair to ask for a rent reduction, any landlords out there?

They have to give the landlord a fair chance to fix everything surely?

It depends. Has the landlord fixed things in a reasonable amount of time?

For example a reasonable amount of time without a washing machine could be up to a month but the landlord might offer money to go to a launderette etc.

Rent reductions aren't normally given especially not if the landlord has aimed to things fixed however if it took two months for a new oven then this would't be reasonable.

None of what you said above would warrant any rent back IMO.