James Desborough
It sounds like there could be a possible blockage. You can go down to your local tool hire and hire some drain rods for around £10 link them together and drive it down the sewer pipe at the bottom of the manhole, if its fullup keep working the rods around until you feel like it has found the opening. Dont be surprised to get a bit dirty and smell, but doing this could save you easily £250 getting dyno rod out or similar drain company.
