This is the most common "problem" and has to do with the water flow and the protection to prevent the pump from running dry. The circulation pump is protected by a switch to prevent it from running dry and the switch is called "Level Switch". Of course, if there is not enough water flow, the heating cannot work either and also the heater has a switch for protection and it is called "Heater". In the video (2922) you can see that the circulation pump symbol flashes when the "Level Switch" is not activated.
The design of the protection is made so there is a switch inside the connection box on top of the circulation pump called “Level Switch”. This is connected to a transparent hose from the end of the pump. When the pump runs and there is enough water, a pressure builds up in the hose which also affects the switch (Level Switch), which is then activated. If the water flow is too small, it will not activate and the control system will turn off after 6 seconds and the pump stops and the symbol for this pump is flashing in the display. The same thing will happen if the water level is too low and the pump sucks air. Or if there is something else that affects the water flow.
In the manual ; https://www.spadealersuk.com/main/dokument/manual/197SG0007B_eng.pdf
it is described as “Water-lacking protection ….”
An easy way to verify if the problem is due to the filter, is to remove it from the filter housing and run without it for 1 day. If the system then works, the filter must be cleaned properly or replaced with a clean one.
If the fault is due to the level switch, it can be bypassed by a cable 092803, 093006, 092931. The grey wire (picture 092803) has no power, it only works as a signal so the power does not need to be turned off if you make a bypass.
Or using the "Abiko" shown in pictures 120009 and 120041. Keep in mind that the protection for running dry is then disabled so it’s important not to leave the power on for example if the spa is drained.
If you suspect that the pressure switch (Level Switch and/or Heater) has not been activated (symbols are flashing in the display), this can be verified by temporarily short-circuiting the contact. NOTE! If this is done with the "Heater" cable, the pump must absolutely be running and providing water flow through the heater.
On rare occasions, it may be the relay in the control board that has burned out. This can happen, for example, due to a lightning strike. In this case, the control board is replaced.