My hot tub states "FLO" on the display which the manual says that the flow switch has malfunctioned. this has occurred ever since i've bought it second hand 2 yrs ago but usually occurred when the jets had been on a while and did not last for extended periods of time.
Now FLO is displayed and prevents water from circulating and being heated (I'm in Michigan!). I investigated it and something must have been jostled because it worked after just looking around--it heated up and worked normally but now it is not working again. Also, I have found the "thermal bulb" that was not attached to anything.

The tub is American Spa, signature series, salvatorian. I have the schematics.

Any Suggestions????

 

Have you replaced filter? You either have a loose connection or the circulation is not enough, could also be hair in impellar.

 

thanks for your reply. yes, changed the filter. unlikely to be hair, i'm bald.

do you know what to do with the thermal bulb?

 

There should be a thermal well for the bulb to go into. It may be around filter compartment, or somewhere in the plumbing.

 

do you think the bulb has anything to do with my problem with "FLO"?

 

I don't think so, it would cause a problem with temp. Getting too hot. Flow is the actual flow through the heater, must be enough flow to keep heater from overheating. Womans hair is usually the problem getting caught in impellar of motor. When pump is on how is the circulation? How long since filter has been soaked in cleaner? Not just sprayed off...

 

When the FLO comes on, does your heater work? If not, it's your pressure switch which can usually be adjusted. It should be attached to the heater manifold and has an adjustment screw/slot on top.

 

Pressure switches should NOT be adjusted except by someone qualified. It is pre set for safety reasons.

 

thanks for your input. it will try to circulate---it normally makes a humming noise just prior to the routine circulating and then the water is circulated. I will get the humming noise and no circulation and then the FLO warning. I don't know if the humming is the heater or not. How would I know if the heater is working?

My diagrams show a pressure switch. it is too dark and cold to look for it now.

any suggestions on how the adjustment should be made (clockwise, etc) or any other useful tips?

Thank you for your assistance.

 

It was simply the pump that was bad. Indeed it can be tested without the water. Once the control panel and pumps were removed I had ability to see the pumps better and then connected the pump to the control panel and saw that the fan on the pump was not turning, and it got hot. A new motor was put in and the water heated up and no FLO error thus far.