We had a problem in a flat we own in Borough. Called a guy called Jao ( 07949 952 556 ) using feedback from this site. He came round the next day, took a look at leak and fixed it promptly.
Now here comes the amazing bit. He said as it was such a small job, there was no charge! This is the first time this has happened to me in over 20 years of dealing with rented properties.
Can't recommend him enough. Great attitude and will definitely be using him from now on.