First of all you will have to check siphon tube of your system. Whether any blockage is there? If it is so, you have to remove blockage.
Secondly, you should put thimble of your sample properly. So that Siphon tube should not get blocked. If you are putting your sample thimble near to siphon tube, it will block the route for siphoning.
If there is no liquid flowing through the siphon then the siphon tube is blocked.
It is also possible that liquid trickles continuously through the tube, but siphon flow never gets started, so the extraction chamber does not go through filling and drainage cycles. If this is your problem you need to increase the reflux rate by increasing the temperature of the solvent flask.
Thank you for your feedback and time Peter Apps. I really appreciate this. Infact, the extraction chamber and the filling of siphon is there but just at the end point when the siphoning is about to occur and it should be occur (siphoning) just at this point, it doesn't work but sometimes when i just adjust the condenser a little and move it from its place then the siphoning occurs. I think there is a kind of pressure or air flow problem, i think. Nevertheless, thank you so much for your response and time Peter Apps, i really appreciate this ...
usually, if you are extracting some material too finely milled, it is possible that some fragment can be drown inside the siphone. In this case you need to use an filtering material such filtering paper thimbles (the most suitable) or some glass wool flocks or some small wadding piece.
Sure, in fact, i am removing vinly acetate from my adhesive sample with acetone in order to get my sample ready for FT-IR analysis... Hope this would be the answer of your question :)
solvent level in my soxhlet extractor is going above siphon tube, from two days it is coming only little bit down when i am increasing heat but the problem with increasing heat is that vapours are coming through condensor ,my solvent is petroleum ether and plant leaf powder...
Peter Apps gave a good advice. I had exactly the same problem - the siphon did not empty. By increasing the silicon oil bath temp from 90 to 100C the evaporation/reflux became a little more intense. Then the system worked as it should. I am refluxing n-hexane.