I have just bought my first house and a drain at the rear of the house is blocked. The sink drains into it. I can find one drain inspection cover but unfortunately this drain is not connected to it. I have tried using drain rods but need to find where this drain connects to.

Any suggestions on finding the other inspection cover? I have even looked next door.

I have tried the stuff you get from B & Q to unblock drains and it didnt work.

When ours blocked up (shared with next door) we got someone out, cost, 40 quid, job done! I'm a Self employed plumber and it wasn't worth the hassle! (and the fact I hate drains :D)

Got a patio at the back? The lid may well be covered up.
Do your neighbours have house designs the same as yours - I'd expect their lids to be in the same positions as your house.

Nick