Slice valves do nothing

[johnnoandy]

Hi folks, I moved into a new home recently with an old tub. I noticed a slow leak where the PVC joins the pump. I figured no big deal, new o-ring and some plumbers tape will fix.

I pushed down the slice valves and turned them (see pics showing closed valves). They closed easily, no issues. However, when I detached the pump the water came gushing out... I waited a bit figuring was just water on the other side of the valve... But it never stopped. 

Has anyone had an issue where closing slice valves appears to do nothing? Didn't appear to even slow the flow. 

Any suggestions?

[CanadianSpaTech]

See it all the time. They have a rubber seal that sits along the plastic slice at the bottom of the handle that can deform and not seat properly in the groove at the bottom of the valve body and water will pour past. Ball valves will work better at stopping water but can get really tight when not used much. Many times I have grabbed a closed slice/gate valve and pulled the handle right out. Now when raising gate valves up from a closed/down position I will use my oil filter wrench that I use to tighten/loosen pump and heater unions and get the one end under the handle and gently pry/lift it up a bit at a time until it lifts the rubber seal out of the groove at the bottom of the valve body. Have not had an issue since. 

[RDspaguy]

I just assume valves are bad and quote for a full drain and refill. I've been stuck with replacing them, water change included, on a D1 once and it won't happen again. If you want to use the valves, YOU can do it. If they don't work, or stick, or break, it's not my problem and I will most definitely NOT fix it for free. I'll be happy to quote you a price on replacing the valves while it's empty.

[CanadianSpaTech]

Yeah more often than not I drain...or work really fast...lol

[Cusser]

I have slice valves on my 1988 CalSpa; they haven't really worked for years, but never leaked externally. Once - back when they worked "OK", I pulled up on one to open the valve, and the handle came up but the internal disc stayed in place, blocking water flow, spa unusable.

What did I do? Well, my old CalSpa had slice valves had 4 screws/nuts holding them together, and I found a replacement valve locally, so just unscrewed the bad valve and installed the guts of the new valve, and buttoned it together.  Of course it didn't shut water flow any better than the former valve, just not a great design.

I advise to replace the slice valves with a real ball valve.