You must get in touch with your landlord about repairs first
You must always contact your landlord first to request a repair. Send a letter or email. There’s a sample letter on the Shelter website. Keep a copy of your letter or email.
Contact details for your landlord
It is the landlord’s responsibility to give you their contact details or the details of their agent.
If this information isn't on your tenancy agreement or you don’t have one, contact Shelter about your rights.
If you rent from a housing association, you should be able to get your landlord's details from Housingnet.
If you rent privately you can use the Land Registry to request your landlords details, for a small fee. But check for their details on any invoices or letters from them first.