How To Clear A Blocked Kitchen Sink
This is a simple guide on how to clear a blocked kitchen sink when the blockage is within the sink trap itself.
Your kitchen sink will have a trap underneath it where water acts as a barrier to stop smells venting from the drainage system back into the house, grease, fat and gunge will collect in the trap if you are not too careful what goes down the plug hole.
You would normally notice that the sink is slow drainage for a while before you get the full blockage as a build up of grease and fat coats the inside of the trap, however if you let a large volume of grease and fat enter the sink when you are cleaning a grill tray or pan you can seal the trap when the warm grease and fat cools as it hits the cold water in the trap. So i am assuming that you have got the plunger from the garage and had a go at clearing the sink from above, this has failed and now its time to remove the sink trap.
The first job is to get as much water out of the blocked sink as you can because when you remove the trap it will all end up on the kitchen floor, use a cup or pan and bail out the water into a
bucket or sink bowl and then flush it down a toilet pan.
There are two types of pipe work used for small bore plumbing they are push fit where the pipes join together using rubber seals and solvent weld where the pipes are glued together, sink traps however are usually (not always) put together so that they can be dismantled by unscrewing one or two joints., this can often be done by hand but sometimes a set of grips will be needed.
In the image above if the joints shown as A & B are unscrewed the U bend will come away from the rest of the pipe work along with whatever water is sat in the sink and pipe work above so make sure you have a bucket or sink bowl situated beneath the trap at all times.
Now this is important so pay attention !, you have removed the trap, the sink has drained into the bowl beneath. DO not take the bowl, stand up and tip it into the sink or you will get very wet feet.
You now have the U bend and hopefully you can see the blockage, clear out the bend with a screwdriver and wash it through with warm water, but not in the sink ! , you can then replace it taking care to make sure all seals are in place and then run water in the sink and monitor the two joints for 10 minutes to make sure there are no leaks.
Its not always a simple job and the blockage could well be downstream of the trap in which case you are as well getting a contractor involved before you start sticking coat hangers and garden canes inside your plumbing system.
Traps in bathrooms tend to be a little harder to deal with because they are often concealed and awkward to reach, contractors can use compressed air and mechanical rods to try to clear blockages before you get to the stage of dismantling your bathroom to access the pipe work.