I have a Sundance 800, Sentry I was using the spa when I noticed that my jets was moving around. I checked the settings and changed my filter. Then I started to get a flashing FLo Message. I read the owners papers and did what it stated ran a hose to make sure of no clogs. When all else fail I can sundance to get a repair person. They hooked me up to a place in Blairsville. Ga, I called and they never call me back. I called many times after that and they never called back. I call and told them that I was interested in buying a new spa, (thinking that it would help" they called me back in 2 weeks and told me that my new spa was in. I never ordered it or did I ever talk to a real person about a new spa. I called a repair man in Gainsville ga. He came out and got on MY INTERNET and went to Sundance home page. He stated " Well they are no help' He adjusted some controls and told me I needed a part and he was going to be back in 1 week. 3 weeks later he never showed. Now my Spa has messges of OH and FLO I called another repair man in Cumming Ga. he came out and stayed for 2.5 hours and told me that he had me going. When I went to look at the spa with him he fixed the HO Or OH meassege but the FLO was still flashing. He also wanted to charge me for the work that he done. SHUUUUUUUUU Okay thanks for letting me vent. No I am back with the same message FLO it is flashing. any Advice.

Get yourself an OHM meter and check to see if there is continuity through the flow/pressure switch, if there is continuity and the pump is running then the problem is that the circuit has the pump activated when it is not supposed to be and therefore a new circuit board may be required, this is a problem that many technicians forget to take into account. Assuming there is no continuity and again the pump is running then a new flow/pressure switch is required. If the pump is not running and there is continuity then the problem lies either with the pump or the PCB, check to see if the pump is receiving voltage, yes = new pump...no = new pcb. if there is continuity and the pump is NOT running then a new flow/pressure switch is required.
Good luck