They simply won't maintain the property. It took over 6 months to get the heating working, another 3 months to take the radiators away. They blame the workmen all the time, then blame you - saying you weren't in (when you know you were). We have had to rectify so much ourselves at our cost, because they simply blag you for months on end - never send anyone round.
I think you'll find, if you look closely, a lot of the reviews about Northwood were written by Northwood.