Spa level dropping when pump turns off

[DougW]

Last fall I had a sand filter replaced with a cartridge filter. Immediately after the filter was replaced the spa water level drops slowly after the pump is turned off. It drops several inches to where plaster is exposed.

I have had Leslie's out twice (as they replaced the filter) and the second time they recommended replacing the check valves which I approved. They installed the valves yet I still have the problem. Any ideas?

FYI I don't use the chlorinator

 

[mas985]

The issue is probably in one or more of the valves and most likely the check valve. All the valves are serviceable and can be disassembled for inspection but start with the check valve first.

 

[DougW]

Thanks for the suggestion, the check valves are brand new. I am not very well schooled in the plumbing. Which valve would be the likely candidate based on the picture i uploaded?

 

[mas985]

Does the spa water level stop above/below/at pool level?

Does the spa level still drop when both the spa suction and return side valves are shut off?

 

[DougW]

I run the pump every day so its hard to say how low it drops. I've seen it drop 4-6 inches over 18 hours. It would have to drop twice that reach pool level.

I haven't tried running just the spa and seeing what happens to the level over a few hours after shutting off the pump. I will try that and let you know.

 

[DougW]

I turned on just the spa for a bit and left the valves as is, the water level dropped about an inch in 3 hours. So, what does this tell me?

 

[mas985]

It is possible there is a leak in the spa. I would leave it that way overnight without the pump running. If the level drops to exactly the pool level and stops, it is most likely internal to the plumbing and probably one of the valves.

However, if the level stops above or below pool level, the leak is most likely external. If is external, the leak is at the same level of the water.

 

[DougW]

I left the pump off for 30 hours and the spa water stopped droppping once it equalized with pool. As both check valves were already replaced does this mean one of the Jandy valves has a leak? If so, is there a way to isolate which one?

 

[mas985]

Yes it is possible that one of the three ways is leaking but since the return side has check valves, it is more likely to be the suction side 3-way. Also, it could just be the handle alignment. If it is not perfectly straight along the pipe, it can leak a little. But it is worth taking it apart for inspection and to clean out anything that might be stuck in the valve.

 

[HouTex]

I left the pump off for 30 hours and the spa water stopped droppping once it equalized with pool. As both check valves were already replaced does this mean one of the Jandy valves has a leak? If so, is there a way to isolate which one?

It works that way on my pool, but it's by design. My spill over spa at the normal (pump off) fill level is just under the level of the rest of the pool. In pool mode it spills over because no water is being taken from the spa, but some water is returning to the spa. When my pump turns off it takes about 10 minutes or so but the water levels off to the same level as the pool which is how it should be. I'm not aware of any separate valve that allows the leveling off to happen.

edit: my second sentence is poorly worded. I meant to say that the normal water level of my spa is just under the level of the wall that separates it from the rest of the pool. After a heavy rain the water will barely cover the glass tiled wall between the spa and pool. When the water is about 3/4 of an inch below the glass tiled wall I add water.

 

[mas985]

When designed properly, a spa's water level should not change when the pump is shut off. Check valves are used to prevent this but they have to be put in the proper location.

 

[HouTex]

When designed properly, a spa's water level should not change when the pump is shut off. Check valves are used to prevent this but they have to be put in the proper location.

I don't believe I have a check value. In any event, I don't care that the water in my pool and spa level off after the pump turns off. It looks better with my pool design.

 

[jblizzle]

@ HouTex, it does not sound like your spa is elevated above the pool like Doug's

 

[mas985]

With a raised spa, it isn't a good idea to have the plaster surface exposed.

 

[DougW]

Thanks Mark, I ordered orings and a diverter in case the silicone is damaged. I will let you know how it turns out.

 

[DougW]

I replaced the diverter and O-rings on the 3way Jandy valve on the suction side (the removed diverter and orings looked ok and there was no debris). Spa is still dropping level.

 

[mas985]

Assuming the suction valve is working correctly, then the only other possibilities are the pressure side valves but it would mean that both the check valve AND the 3-way valve were leaking. Seems unlikely. Otherwise, it has to be an external leak although that would be an unlikely coincidence that it stops at the pool level. I can't think of any other way for the water to go from the spa into the pool.