Thanks for your question.
If the water pressure is such that you do not have a supply of water that a reasonable person would consider adequate then this is, in effect, a disrepair issue. You have a right to a property in repair and can enforce this against the landlord.
You should formally write to the the landlord (copying in the agent) specifying the disrepair, making a list of the reasonable repair required and ask that he make those repairs within a reasonable time (eg. 14 days). State that if the landlord does not make the repair within that time you will pay to have the repairs made and will seek to claim the expense from him and are prepared to make an application to court if necessary.
If the landlord does not make the repair you can pay to have it done and then write formally to him requesting the payment of the cost, again within a reasonable time). If he does not pay you can issue a claim for the money yourself through Her Majesty Courts Service's online service: http://www.moneyclaim.gov.uk/. Write to them first asking for the money and stating that you will issue a claim if it is not received.
Its pretty cheap and straightforward to use.
Open a file, send letters by registered post, keep copies of everything for use in any claim you may choose to issue at a later date.
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