Hi, I have a 2 bed flat in london that I let out to 2 friends on a fixed short let assured tenancy for 12 months. A month after they moved in, they complained about not hot water not flowing out of the shower; it was trickling out of the tap in the bathroom. So far I have been dealing with this and have an agreement with British gas to install a combi boiler which would cost me roughly £5K, in the mean time, for last month, the guys demanded a compensation for the inconvenience and we agreed an £100 pound reduction in the rent due to pay for their gym membership, where they claim they now have their morning shower. Surprisingly, for this month, without any consultation with me, they decided to pay £300 pounds, meaning a £700 reduction. They calculated that they been without proper hot water flow for the past 60days (inclusive of the already compensated month), hence at the rate of £10 per day for the inconvenience caused and £100 for their continued gym membership for the month, they reckon they deserve the £700 pound reduction in rent. Can someone please advise if this is legal, as they acted on their decision without any form of agreement with me. I am now looking for a private plumber to install the combi, hopefully within a week. Is there any way I can get my money back, or have these guys leave my flat. I really need help as I have a huge mortgage to pay. Thanks, Toy