Broken spring on Hot Tub waterway flapper valve


Aug 4, 2020
I have a hydropool hot tub and am having low flow issues. Done all of the basic things and then some :
- good water level
- purged air
- new filter
- rebuilt motors (bearings)
- new wet ends
- new balboa spa pack and top side controller
- valves open
- temp reading between sensors in test mode is ~ 1degree difference

The only thing left is that there is a flapper valve at the bottom of the filter and I noticed that the spring is broken. Looks like the flapper lays flat and does not go vertical on its own. Could this be causing the low flow faults ? If so how do I repair it since it looks like it is impossible to change from the top.

Any help would be greatly appreciated


Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
Fletcher, OK
most flapper valves are used keep water in the pump when the pump is off and once the pump starts it opens up... So with the pump working it should be open, if it is not open then that would cause a low flow issue... It also may be a low flow sensor that is not working, do you have a manual?


Aug 4, 2020
Yes I have all of the reference material and have read just about everything out there. Spa pack has M7 technology and is brand new. Weird thing is that if I switch the wiring on the 2 speed motor so that the high speed comes on during filter cycles, everything works fine. Only a problem when trying to filter in low speed. Continue to get LF or DR faults. Im thinking I am not getting enough through the heater but cant figure out why.


In The Industry
Mar 21, 2020
Cabool, Mo
Well, a flapper valve doesn't have a spring, a spring valve does. The plunger gate does not hinge, but pushes back linearly in the valve body. I usually see them used for blower check valves or in a filter bypass. But I am not familiar with that brand so couldn't say how they may be using it.