Toilet no flushing properly.

[MickBrown]

A collegue of mine has come across the following problem. Downstairs toilet in newish house (prob last 10 years) when flushed partially fills the bowl then flows away. Toilet has durgo valve on stub stack that is fitted just below the spillover level of the basin. Cloakroom backs onto cloakroom of adjoining property, adjoining cloakroom has same problem. He mentions blockage to owner but she says the neighbours had dyno rod out who completed a full survey of their drain and could not find a blockage. I am assuming the 2 drains join somewhere but there are a severe lack of inspection drain inspection hatches. He removed the durgo valve and the toilet flushed correctly, so he thought that the durgo was faulty. He replaced it the durgo but flush problem stayed the same, he tried a second durgo in case replacement faulty but problem persisted. When toilet flushed the basin (this feeds into the stub stack as well) gurgled, if the plug is inserted and the basin overflow blocked the flush problem is not as bad. He also tested by holding the durgo valve open manually, the toilet flushed normally in this situation. Anybody any theories or other tests he can try?

 

[ShaunCorbs]

Blockage

 

[Riley]

Definitely a blockage somewhere

 

[MickBrown]

Blockage

That's what I thought, but neighbour has same problem and Dyno Rod could not find a blockage. Doesn't mean that my collegue's customer doesn't have one, I have a faily long worm I can put down to see if it meets any resistance.

 

[Riley]

If it works without the Durgo it can usually only mean blockage or at least partial blockage somewhere

 

[snowhead]

Just to confirm, as above, there's definitely a partial blockage.
It's nothing to do with a faulty Durgo.

Take the Durgo off and rod down the stub stack.

If Dynorod have used a camera, they would have seen the junction from the house with a blockage.

 

[WC1]

Do as above and if not then perhaps get a proper local drainage guy (which dynorod are not)! Did they give you the video file of the survey?