[decaboy]

My shower drain tends to overflow when there is more water than it can drain. It still drains it, but it does it slowly... I think its weird because when I look down into the shower drain I see standing water in it and whenever I turn on my shower head the water starts to overflow, which I start to turn the shower head off. The water eventually drains to a point where the standing water stays at the same level. I have poured almost half bottle, the drain clogging agent is called "Instant Power." What should I do if the water always drains but than it stops and becomes standing water at a specific spot?

Thanks in advance

 

[Just Bill]

If it is an old house, say before 1970, it may have a cast drum(bell) trap. They are nearly impossible to clean with a snake, and the cleanout cap(if accessible) is usually impossible to remove. In addition, years of use have added buildup to the wall of the galvanized drain line. If you can get a snake down it, that is your best bet for opening it up.

 

[LateralConcepts]

My shower drain tends to overflow when there is more water than it can drain. It still drains it, but it does it slowly... I think its weird because when I look down into the shower drain I see standing water in it and whenever I turn on my shower head the water starts to overflow, which I start to turn the shower head off. The water eventually drains to a point where the standing water stays at the same level. I have poured almost half bottle, the drain clogging agent is called "Instant Power." What should I do if the water always drains but than it stops and becomes standing water at a specific spot?

Thanks in advance

There should always be standing water in there. That's the p-trap you're looking at. It keeps sewer gases from coming back into the house. You should avoid using drain cleaners. Clear it with a power snake (3/8" cable). If you don't know how, or aren't comfortable doing that, hire a drain cleaning company. It's most likely just accumulation of hair, soap scum, etc.