"FL O" error - Should the circulation pump always run?

[RobBritinCali]

I have an older Sundance spa that came with my vacation home. When visiting this weekend, I found an "FL O" error on the tub and it would not heat. (All other functions, blowers, lights etc work). I took out the circulation pump, it appeared to be stuck and then it freed up. I refitted it but it still did not run. I also tested the pressure sensor and tripped it into closing which started the heat but still no water flow (Stopped that after 5 seconds to avoid any burn-out/over heating etc). I'm pretty certain the circulation pump needs replacing, but I want to check it first but am not sure if it constantly runs or not - If it does then I know I should expect a constant voltage to it whilst the spa is on.

Thus, my question is: Should the circulation pump be constantly running even when the spa is not heating? Any advice would be great, thanks

[dg98adams]

I have an older Sundance (Cameo).

 

I think mine heated when the filtering was running (220v).... the filtering was controlled by a mechanical timer switch that was user controlled for "how & when" in a 24 hour period... The timer switch went bad once, as I had replaced it.

On the pump that you "freed up", is there rust between the pump and the motor on the shaft? You may have a leak there at the seal that caused the motor/shaft/bearings to wear.

Also, have you checked the filter? when they clog up they can inhibit flow.

 

[RobBritinCali]

Thanks for your response. The filter is new and I checked the flow lines through from that, though the heater and into the spa and there are no blockages so I've eliminated that as the issue.

I couldn't see any mechanical timer on the board either and the circuit diagram (attached) doesn't appear to snow the presence of one either.

As for the pump- it wasn't rusty but the back of the impellor and around the shaft had lots of mineral deposits on them (possibly Chlorine etc) which game me the impression it had leaked possibly. I couldn't see any other signs of damage on it though

Thanks

spa circ dia_1.pdf