Newbie needs help with a Balboa hot tub heater problem

[vauxhallmaniac]

Hi All I am a " Hot tub Virgin " and need some help   !!!!  I have just purchased my neighbours tub its a spaform Milano with a Balboa GS501SZ spa pack... got it at a good price as the heater is not working, on first inspection I had no power to the element ( resistance checked out ok on element & no short ) did a little googling & the 12v relays seem to be an Achilles heel on the board de-soldered the lower one & broke it apart ( contacts all pitted & burnt ) so ordered & replaced all 3 heater relays finally got it back together today. Its now got power to the heater element but trips out with a HFL code. So more googling & it gives a list of possible causes one of them being a dry/unprimed element!!  when the element was powered for the first time it made a sound similar to a kettle being switched on or a kettle low on water!!
 This is where my knowledge of tubs gets sketchy !! I assume possible dry element, when I switch the tub on it goes through a number sequence then to PR for a few minutes (I assume a priming pump noise should be heard???) but there isn't a peep out of it, so when in PR I have run the pumps on the buttons hoping to fill the element tube. It then goes through what seems to be a systems check the heat light flickers for approx 1 minute or so, one of the pumps pushes water out of the upper (neck line) jets, the heater light comes on full (power to element ) and runs for a few minutes before tripping out & HFL again!
I'm hoping a techie on here can point me in the right direction!!!     should a pump run when in prime mode? it has 2 pumps and both run when switched top side, could the heater tube be empty? ( the tub was filled up 2 weeks ago I would assume any air locks should have dispersed by now ?? ) any pointers on what else can cause the HFL trouble code. Sorry its a bit long winded was hoping to be bubbling away today !!!!!!!!  thanks in advance  Simon

[Kev B]

The V series Balboa has no pressure switch so it will allow the heater to run without water flow. When you turn on the breaker, you can turn up the temp button and hit jets to turn on heat circ pump. (whatever pump is pushing water through the heater) PR mode has nothing to do with priming the pump, you must do it before heater engages.

[vauxhallmaniac]

Thanks Kev that clears up the PR mode       so anyone got ideas on my HFL shut down as the second time I tested it I ran both pumps before the heater switched on and it shut down the heater after a couple of minutes with HFL again!!

[Kev B]

Possibly the "Heater Flow is Low" (HFL or HL).

During Heating, this message indicates a Possible Low Flow Condition.  There may Not be Enough Water Flow through the Heater to carry the Heat Away from the Heating Element.  Heater Start Up will begin again after about 1 Min.  Check for Water Level, Flow Restrictions, Closed Valves, Air Bubbles, and Pump Prime, or contact your Dealer or Service Organization.

1.   Low Water Level.
2.   Blocked Suction Fitting.
3.   Blocked Skimmer.
4.   Dirty Filter.
5.   Too Many Closed Jets.
6.   Closed Slice Valve.
7.   Heat Related Pump Not Running.
8.   Heat Related Pump Not Primed.