Hi everyone,
Hope somebody can help!
Went to a job on the second floor of an office block. Problem reported was dishwasher blocked and not draining. Upon investigation, found that the problem was with the sink waste which was blocking. Dismantled the u-bend and one wet cupboard base later, water had gone. Couldn't dismantle joints as solvent welded but fed drain snake down vertically to full extent (approx' 5 metres) and found no blockage. Don't know how to post sketch so will try to describe pipe route!
From u-bend, 40mm dia horizontally 250mm then 90 degree down vertically to base of carcass, 100mm horizontally to swept tee (with access plug in) then 90 deg horizontally for 100mm, 90 degree horizontally again for 100mm then reduced down to 32mm dia and enters into 50mm dia vertical stack. The floor above does not have any sinks so the maintenance guy reckoned it was only used above as a condensate for air conditioning units. The pipe drops under floor space and runs horizontally down void into a ground floor compressor room. Here the pipe runs horizontally for approx' 2.5 metres then into a swept tee with access plug then originally dropped from ceiling to 200mm above floor then ran 600mm horizontally before discharging into the floor via a Marley reducing boss. After quizzing some of the staff, it appears that somebody was called in to check out some bad odours and this resulted in the long vertical drop in compressor room been split and an elaborate u-bend formed using 50mm dia solvent weld to create a extra seal. I found that by putting water in the sink, whilst it discharged VERY slowly, if i started to undo the access plug at base of cupboard, the waste emptied immediately. Also, filling the sink and going to floor below (compressor room) and undoing one of the access plugs created the same effect! Any ideas?? What about a anti-vac trap under sink??
Many thanks in advance and apologies for long post!
Gary.
Hope somebody can help!
Went to a job on the second floor of an office block. Problem reported was dishwasher blocked and not draining. Upon investigation, found that the problem was with the sink waste which was blocking. Dismantled the u-bend and one wet cupboard base later, water had gone. Couldn't dismantle joints as solvent welded but fed drain snake down vertically to full extent (approx' 5 metres) and found no blockage. Don't know how to post sketch so will try to describe pipe route!
From u-bend, 40mm dia horizontally 250mm then 90 degree down vertically to base of carcass, 100mm horizontally to swept tee (with access plug in) then 90 deg horizontally for 100mm, 90 degree horizontally again for 100mm then reduced down to 32mm dia and enters into 50mm dia vertical stack. The floor above does not have any sinks so the maintenance guy reckoned it was only used above as a condensate for air conditioning units. The pipe drops under floor space and runs horizontally down void into a ground floor compressor room. Here the pipe runs horizontally for approx' 2.5 metres then into a swept tee with access plug then originally dropped from ceiling to 200mm above floor then ran 600mm horizontally before discharging into the floor via a Marley reducing boss. After quizzing some of the staff, it appears that somebody was called in to check out some bad odours and this resulted in the long vertical drop in compressor room been split and an elaborate u-bend formed using 50mm dia solvent weld to create a extra seal. I found that by putting water in the sink, whilst it discharged VERY slowly, if i started to undo the access plug at base of cupboard, the waste emptied immediately. Also, filling the sink and going to floor below (compressor room) and undoing one of the access plugs created the same effect! Any ideas?? What about a anti-vac trap under sink??
Many thanks in advance and apologies for long post!
Gary.
it`s come up a couple of times before - Basically someone putting the extra trap in the 50mmpipe has caused the problem 
