CMP 3 way diverter valve stuck, poor water return

[utnuc]

Hey guys, I noticed that my filter pump was running low on inlet water the other day when it was making a lot of noise. So I cleaned all skimmers and filter baskets to no avail. At minimum pump speed the filter pump barely stays primed, and the downstream filter pressure is almost 0. The pool equipment is 15 feet below the water line and has never had this problem.

So I set about trying to figure out the issue. The skimmer return suction is very low, I can't even pull leaves off the bottom using my pole hand vac. My initial thought was that the skimmer line was blocked up, so I put a pipe snake 25 ft down the skimmer line and didn't get anything back. Then tried to alternate my CMP (I think) 3 way diverter return valve from skimmer to drain to try and get any obstruction to clear, no difference there but then this valve started to become very difficult to turn. It won't go past 3 or 9 o'clock into its normal operating location of 12. I think the valve is either busted or a kids toy is lodged inside.

Should I take apart the valve and see what's up? How do you recommend going about blocking skimmer and drain return (deep end inlet) lines? Tennis ball in skimmer and large tub with sand bag on drain? Just want to get advice before I mess anything up or go diving in 48 degree water...

 

[ajw22]

Hey guys, I noticed that my filter pump was running low on inlet water the other day when it was making a lot of noise. So I cleaned all skimmers and filter baskets to no avail. At minimum pump speed the filter pump barely stays primed, and the downstream filter pressure is almost 0.

I don't think you have any problem. This is normal behavior for a very low pump speed. Up your pump speed a bit until you get a better water flow.

We are used to seeing how the equipment behaves with single speed pumps running at maximum flow rate or 2 speed pumps running at low speed which is half full RPM. With a VS pump you can run lower flow rates, filter pressure will barely register, and the pump basket will get an air bubble.

Then tried to alternate my CMP (I think) 3 way diverter return valve from skimmer to drain to try and get any obstruction to clear, no difference there but then this valve started to become very difficult to turn. It won't go past 3 or 9 o'clock into its normal operating location of 12. I think the valve is either busted or a kids toy is lodged inside.

The valve for your skimmers is your suction valve, not the return valve.

Take oyt all the screws and open up the diverter and see what is going on in the valve.

 

[utnuc]

Thanks for your reply. When I increase the speed of the pump past minimum it goes dry and empties the filter basket reservoir of water.

I need to find a way to prevent my pool from emptying while I service this valve. I've read of people using a big rubber mat for the deep end drain, and a tennis ball for the skimmer. Guess I'll give it a go.

 

[ajw22]

Thanks for your reply. When I increase the speed of the pump past minimum it goes dry and empties the filter basket reservoir of water.

That is usually a suction side air leak.

Suction Side Air Leaks

If you see air bubbles coming out of the return lines in your pool, you likely have a leak. Some signs that a suction side plumbing leak has occurred include: Read more

www.troublefreepool.com

I need to find a way to prevent my pool from emptying while I service this valve. I've read of people using a big rubber mat for the deep end drain, and a tennis ball for the skimmer. Guess I'll give it a go.

Use a potato for a plug.

 

[utnuc]

Update on this: it was a huge wad of leaves that somehow got stuck in the valve. Had to drain the pool ultimately to get the repair done. Added some isolation valves so I wont have to drain it in the future for equipment repairs.