I would suggest buying starsan and using that to sanitize instead of bleach. The bleach smell & taste could also linger into your brew. I would also sanitize your chiller in a bucket before putting it into the wort. I know many people just boil them clean, but I like to sanitize mine. Also try using a packet of dry yeast. Like pfooti says, its a process of elimination. Another option is to try bottled spring water if you are using tap water.