They tried for 45 minutes to clear a blockage in our sewer with an 'electric eel' but was unsuccessful. I asked them to try once more and they were able to 'breakthrough'. However 1 week later and the sewer had blocked again. I decided to do it myself (you can hire the electric eels from kenards etc) for under $100. After 2 or so hours I was able to clear out the drain (with large clumps of roots being extracted). It appears that when the drain was initially cleared by them that they had just used a simple narrow cutting head to 'breakthrough' the blockage and not actually cleared it properly. I would be unwilling to use this company again, further, I would not use a plumber again for such a relatively simple job I can do myself.