Leaking when in Filter mode

[poolinwales]

Hello,

Please can someone help me

So I have a sand filter I have a PAC-FAB handle (which is basically the same as Hayward 710X.

So the issue is that when I have it on filter is it leaking water (at quite a rate). The reason I know if that the pool water level goes down. So this is what I have tried:

- I have replaced all the O rings
- I have replaced the spider gasket (and properly re-installed with silicone etc.)
- I have replaced the spring in the handle (i.e. I wasnt sure if if that tension had gone then it wouldnt be pushing down on the spider gasket.
- Checked the handle is on the right way

Does anyone have any other ideas what I could try. Everything looks in decent condition.

Many thanks

[Teapot1]

Where is it leaking to?

[poolinwales]

I presume the backwash or the waste. There is no visible water.

[Teapot1]

Ok, internal multiport valve leaks are reasonably common. Can you put a bucket under the waste pipe to verify?