Assuming the fixture or fitting belongs to you as the landlord; you’re required to carry out necessary repairs only once you have been notified of a problem by the tenant. You can arrange to visit the property for an inspection, giving a minimum of 24 hours’ notice or whatever time period is specified in the tenancy agreement according to your landlord right of entry. Sticking to the rules on notice periods is a legal requirement, and it’s also going to be appreciated if your tenants work from home.
You may sometimes be happy for the tenant to arrange the repair themselves, but you cannot require them to do so if you are legally responsible. It’s worth asking the tenant to get more than one estimate – after all, you’re paying the bill.
Where you either want to do the repair yourself or arrange for a tradesperson to carry it out, you must give the required notice period.
It’s worth remembering that when a tenant installs their own appliance, they are responsible for its safety and maintenance and for repairing any damage it may cause. For example, if they installed their own washing machine, they’d be responsible for water damage following a leak.