BP500 vs BP501 (replacement)

[Bmay]

I have a hot tub made by Clarity Spas. Breaker kept tripping so upon inspection, the control board (not sure of proper terminology) had a short connection on one of the power wires and roasted the board beyond saving. It was a BP500 model. I did some research and could not find a replacement bp500 to save my life. In reading and reviewing it appeared as though the BP501 would work as a replacement. I got the BP501 and have installed it. It works, but not all functions are right. I installed it, the main pump and auxiliary pump worked to purge the air out of the lines. I then turn off the purge start up mode to get it to begin heating and the main pump which either runs the slow speed to just heat while not in use, or the high speed to control half the jets isnt working right. The slow mode works and appears fine. When i hit the button to turn the jet mode on it makes a loud noise like the pump is seized or something then stops. The auxilary jets work great. I swapped the connections for the pumps to make sure it wasnt the pump, and the high speed on the main pump works fine. Therefore its something with the board i guess.

 

Anyone have any ideas?

[xwaveone]

There is a lot to your questions to answer and I will be brief. 1) VS501 has plugs for 2-speed pump 1, 1 speed pump 2 (that then uses the blower receptacle) and a circulation pump.  When circulation pump is used, the setting to have pump1 function in both speeds, has to have both A5 and A9 dip switches ON.  The circulation pump will then run continuously with 3 deg F setback. 2) BP501 as it comes from the factory comes only with a 5.5kW heater.  To install a 4.0 kW unit it would have to be a field conversion.  For example we can do it.  Whether an E14 will work with M7 spa pack equipped with a 5.5 kW heater is a bit of a crap shoot.  In principle it should if the flow resistance in the circulation circuit is low enough.  For sure if the circulation system doesn't deploy 1-1/2" piping that would be a red flag.  However when a 4 kW or 3 kW heater is substitute the flow requirements drop from 23 GPM to the kw ratio ( 4/5.5 or 3/5.5) and in that case I would not have much worry, if the piping is 1-1/2" which it should be with a E14.   Balboa told me they tested the BP1500 (which has a 4.0 kW element) with the E14 and it worked fine. shareit vidmate app