no
to unstop condensate drain lines
A sectional rodding machine is the best bet.
Try threading a wire (coat hanger etc.) or low pressure air through drain
Depends on how long your drain line is and where the stoppage is. You could rent a drain snake from a hardware store but if you don't know how to operate one I would suggest you call a plumber or roto rooter man (look in the yellow pages).
OF COURSE
One way to open a slow kitchen drain is by using a plunger on the drain. If the drain is still slow put some baking soda and vinegar in the drain to loosen any debris that remain in the drain.
Kitchen sink and washer use same drain line. Drain line clogged causing backup of drainage from washer into kitchen sink. Have drain line unclogged to take care of problem. If drain line not clogged, check for proper venting of drain lines.
They should not be cleaned in the kitchen sink and YES, it will harden in the drain.
Bathroom or kitchen should be square and level. The plumbing drain lines need slope to drain properly.
another clog, further down the drain pipe. You need a drain snake.
Your kitchen sink drain and your shower drain are connected to a common drain line. There is some sort of blockage in the drain line past the point where the shower drain ties in. You need to call a plumber to run a snake through the drain line from the kitchen to where it ties in to the main drain of your house.