Opening pool - backwash pipe has water coming out while pump is on filter

[Arcpool13]

We are opening our pool ourselves solo for the first time. We have the winter plugs removed and the valves open (we think in their correct spots!).

The pool is currently running on filter, but there is water coming out of the pipe that is connected the filter. I have attached photos. The pipe coming out on the left from the filter has some water trickling out. Any guidance? Water typically only comes out of that pipe when we are set to rinse or backwash.

 

[Texas Splash]

That is generally a sign that the spider gasket (or key diverter) in the valve is stuck, pinched, or going bad. Winter can play havoc on some of these things as well. Are you careful to turn the pump off when changing selections? Do you usually turn the valve in the same (one) direction to avoid a chance of pinching the gasket inside? Just a thought. If you haven't done so already, you might turn it off and run the valve back and forth a couple times to see if it's just pinched, otherwise it may be going bad. You can remove the screws on top of the MPV and inspect.

 

[Arcpool13]

Thanks again. So we have now removed the MPV, and this is what is underneath the top of the MPV. IS the gasket the yellow piece of plastic or is that going to be on the other half of the port which is still on our filter. It looks like the yellow piece of plastic is a little cracked, should we just pop that piece of plastic out and find a replacement part?

Many thanks.

 

[Texas Splash]

It looks like you have the Key and Stem Assy out of the valve as seen as part #11 HERE. If that's what I am seeing correctly in the pic, then you would just replace the entire part. Since you see a crack, it's easy to understand why water would be running through a different channel (i.e. WASTE) when it's not supposed to. Quite a bit of pressure in there when operating.

Your valve looked a bit worn on the outside, so you might consider the long-term. You have the option of changing just the Key & Stem portion, and perhaps a spring or two while you're at it. But if the valve is as dated as it appears, you might also consider replacing the entire MPV. Certainly your call depending on how it all looks on your end and evaluating the cost benefits.

 

[Texas Splash]

There is also part #12 (gasket) on the diagram HERE that would apply to you. Look at everything from the gasket above (springs, washer, etc) up to the O-ring (item #6. To be sure, look for any part number or model ID info on the valve just to be sure the illustration I'm showing you is teh exact match.

 

[Arcpool13]

Thank you very much! We went ahead and replaced some of the parts, and that has solved the problem for that. Your reply makes us feel better about buying those parts, and at the end of the day, is much less than I am sure what the pool service company would be charging for opening, and who knows if they would actually check out our equipment for this wear and tear, based on past I am guessing not. Thanks again!