Open Flow Switch

its not the water level – I took out the filter and there was a plastic type cover 3/4 over the grey thing with all of the holes in it – I assume something that should have been removed during installation. The filter keeps popping off – if I turn it tighter then we get the error message so at this point I have no ideas other than we have been getting this error a lot when the filter it installed but if the filter is removed or pops off the error goes away.

Open Flow Switch – Proper flow of water is inhibited or a flow switch has malfunctioned. Check for proper water level or a clogged filter. Your heater is deactivated and your filter and/or circulation may also be deactivated.
If condition persists contact your Sundance® Spas dealer or qualified service technician.
Please note the Open Flow Switch message can also appear if the pump has not been primed after the spa has been drained and refilled. If you suspect that this is the case, see the instructions in your owner’s manual.


  1. Nigel


    Hi Jason. The white cloth mesh over the grey filter grate screen is to help prevent oils and greases that bypass the filter proper from passing into the pump and back into the spa water. The cloth mesh should be replaced on a regular basis to help protect the spa and water. It sounds like the inner core filter is getting greased up and causing the error code. Consider replacing the inner core filter. The inner core filter is not re-usable and should be replaced when it is greased up. Typically the inner core filter will cause that error code when it gets greased up.

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