To make a long Story Short, its been a few years now and had a few costly growing pains but I'm kinda perplexed on where I need to go with this problem. I had an old Spa tub (Down East Spa's I believe) with the Balboa Lite Leader board w/ the 4kW element I believe...The spa breaker tripped in the winter and the tub froze...I rebuilt the thing from the ground up putting in completely new plumbing and mirroring all the plumbing sizes and reducers in the same places that were currently used before, I also put a new (correct size) wet end to a aquaflo pump, and a new BalboaVS spa pack (upgraded from the aincient Lite Leader Box)... To make a long story short The tub runs fine on low speed, gets up to temp, and is very confortable (and it lasted all last winter)...however when I turn on the high Jets I get about 30s-1min of operation before it sounds like the motor bogs down and the High limit trips...I think that this new VS spa pack has a higher Kw Rated element, and since it runs on 2 temp sensors wired into the inlet and outlet of the heater tube I think that I'm not able to move enough flow across the 5.5Kw Element to keep the temperature rise within whatever set limit the control box is comfortable with...so the system shuts down on High Speed (but once again runs flawless on low speed)... I've replumbed the thing to run wide open this year (Jets + Whirlpool Jet) instead of a either/or option I had setup before, so I could get max flow/low pressure out of all my jets and my large whirlpool jet...Yet it still clicks off and says high limit (it even did it when I tested it with cold water from my initial fillup... My question is this...do you think its a pump/flow problem, ( as in me not moving enough water across the element )...and if it is, can I open up the heater box and swap out the 5.5Kw element in it, for the lower Kw element I still have from my old Balboa Heater? If that won't work, what pump/motor combination do you sugguest I go with in order to move enough water over the 5.5Kw element so that I can possibly enjoy my high jets this winter? Any help would be appreciated... Regards, " title="Very Happy" />

Sounds like you have a problem with the 2 speed pump - these are notoriously unreliable.

It sounds like there is a problem with the winding on the higher speed. As you have a new controller, and a new wet-end, I'd suggest its very likely to be the pump.

If you notice a flow drop when it "sounds like the motor bogs down", then this is causing the flow rate across the element to drop to an unacceptable level, and causing the overheat cut out.

Personally, I'd replace the dry-end of the pump, provided that the above is correct.

You may have put an oversized impeller on your motor. Do you happen to have your motor specs and the part numbers for the wet end you bought?

I know its not the wet End...I made sure I got the identical wet end and verified that the part numbers were the same when I replaced it...I haven't switched the element yet, I'll probably go the route of replacing the motor - I might even buy a whole new pump/motor assembly just to save the hassle, at least my plumbing is set up that I can isolate the pump and work on things in my garage if I have to this winter...