Water level on Spa (attached to pool) drops when not used


Active member
May 12, 2015
Dallas, Texas
Our spa/pool was recently remodeled. Full pressure test done before it started. Two of the spa jets were leaky and fixed.

The pool equipment and pool itself sits lower than the Spa, so gravity tends to flow water back towards equipment.

When the pump is running the water flows up thru fountain plumbing and spills over from spa into pool.

When the pump isn't running the water level typically holds high in the spa near the same place when the pump was turned off.

However, during cooler weather (50s) the level seems to be dropping a few inches per day when pump is off. I've changed all the check valves but it's still happening. I'm thinking that in cooler weather some seal is contracting slightly. Could it be inside a diverter valve? ideas?



Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Tell us where your check valves are located in the plumbing flow.

The check valves should be before water gets to any diverters so diverter leakage should not be a factor.


In The Industry
Mar 21, 2020
Cabool, Mo
Can't have a check valve on the spa suction that starves the pump, so unless the check valve is on the pool suction it could be the suction side jandy valve. If the valve rests in pool mode overnight even a pool suction check valve wouldn't stop it from returning to the pool.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

Show us several pics of your equipment pad, so we can see all the valves and associated equipment.

90% of the time, the problem is with the check valve on the pipe going to your spa jets.

When your pump is running, and the spa is overflowing into the pool, does the water enter your spa from the spa jets or some other way?


Jim R.
Thread Status
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