You shouldn't touch any of the appliances in the property Chloe. The
maintenance and repair is all down to the landlord or owner / manager of a
rented flat. For you to have to do these things by yourself is not in
your
rental contract, as all fixed appliances in a rented property must be
maintained by the factors.

Leave it alone and play bloody hell with the landlord. Tell them you
stink
all over because you can't wash properly, and they'll get the cleaning
bill
for your smelly clothes as well.

This advice is basically sound but as someone who has been both landlord and
tenant for many years I would advise you to approach your landlord or his
nominated agent calmly and rationally. Sounds like he will know perfectly
well that this is a second shower so you can hardly be depending on it for
all your washing. And if he is halfway decent as a landlord he will
recognise this as a perfectly reasonable request to fix an appliance and act
on it because he wants you to stay happy.