On my pool my backwash hose is running water out of it when iam not backwashing why is this doing it how do i?

Question

how do i fix it

Answer 1

Unless you had an overheat situation ( either running the pump dry or turning off the pump while a pool heater was firing), it'll be what's called a keystem gasket. It's located inside the multiport ( the dial you turn to the backwash / filter setting). If there's a nick or deformation in that gasket, it'll leak out the backwash line. The gasket can go bad if your water chemistry has been way off, with age or if you have a bad habit of turning the multiport handle without shutting off the pump first.

To repair it yourself, you'll need the proper gasket for your particular filter make and model, the tools to remove the top part of the multiport ( usually just a phillips s***w driver and wrench), a rag or towel to dry the area the old gasket sat in for gluing and the proper glue to bond the rubber and plastic.

This is a repair that a somewhat handy homeowner can do if they have the right glue ( I used to use a cyanate based glue). You just need to make sure that you reassemble the top portion of the multiport back into it's original position on the base. There is usually some form of indicator , such as a s***w/bolt hole tab that has a flat side on both the top and bottom halves of the mutiport.

There's a temporary solution you can use to stop the leak if your local pool shop has to order in the gasket and that's to install a ball valve in the hard plumbing on the backwash line.  Open the valve when you back wash and close it when you're done.

Answer 2

If you have a multiport valve, it probably has a bad spider gasket. If you remove the top of the multiport, you'll see the spoked gasket. They can be purchased from your local pool store.

If you have a push pull valve, the puck orings are probably bad in it.