Shower

I have an apt that I recently put a new shower valve in (two handle with diverter) and as soon as it is turned on the shower instantly comes on without pulling up the diverter valve. Any suggestions would be appreciated. THanks!

Some things which can cause that:

>too high pressure in the house water system
>valve body installed upside down
>connected from the valve to the tub spout with PEX or CPVC .

If none of these apply, post back for more suggestions.