Drain blockage issue with manhole

[andyb19701970]

live in a 1920 house and the drains often get backed up ,after looking in one of the manholes i noticed the inlet pipe is lower than the outlet pipe 4 inches being the difference in pipes not sure how to solve problem

 

[fourtytwo]

I assume what your not saying is the manhole is partly filled with water!! It's probably a style of intercept with an invert and an overflow for when the invert is blocked, what your are seeing is the overflow. You need to unblock the invert, if you dont have drain rods try a hose on full blast pushed down to the invert level below the water (below the overflow pipe), excess water will simply flow away though the overflow until you have cleared the invert. If it's a long term blockage it's probably full of compacted paper so you may need to get quite agressive within the bounds of not cracking the earthenware. Anybody knows another name for this thing please change invert accordingly!

 

[freddiemercurystwin]

Got some pics?

 

[Deleted member 267285]

the inlet pipe is lower than the outlet pipe 4 inches being the difference in pipes not sure how to solve problem

Are you sure? As per @freddiemercurystwin, any photos?

 

[HERTS P&D]

Blocked interceptor, very common, get it jetted or try rods first.

Andy

 

[Nige F]

Interceptor AKA Buchan trap . Either way they're a buchan nuisance