Hello everyone, i bought a house that came with an outdoor, gazebo located 2004 Marquis Spa Reward hot tub. The previous owner told me the topside control LCD display didn't work, but the buttons work, other than that she stated it was all in working order. After speaking to a few people about setup, i filled it with water and flipped the 50A GFCI breaker located in the gazebo, it breaks immediately.
I had an electrician come over, he put in a new breaker, and tested the electrical coming from the main at the house, everything is ok to the box. He then pulled the electrical out of the main control board(3 wire 220v, board is a balboa MTS2KU), capped the lines, and tested, all good. so it only breaks the GFCI when connected to the tub. He then systematically unhooked from the board both pumps, ozonator, lights, and topside control, and tested, still breaks with all of them unplugged. Essentially the only thing receiving power is the heater and the board at that point and it's still breaking.
The only anomalies we discovered are as follows, when the breaker goes off, nothing happens at the control board, unless you have the topside panel unplugged, in that case the main board clicks twice, but the breaker reacts the same. also, once since ive been in the house, before there was water in the tub, the breaker turned on straight away and everything came right on, i immediately turned it off due to there being no water in at the time. it only did that once, other times when empty the breaker would break. Any idea what my problem is? The board, the heater? thanks in advance.