Sundance Bahia 780 not heating

[Spasome]

My 2005 Sundance Bahia 780 stopped heating. Everything else works including the heating light on the control panel. After it failed it made a buzzing noise when the heating light was on but that has stopped happening. It also initially tripped the ground fault breaker that supplies it from its dedicated breaker box 8 feet away. Now it doesn't buzz or trip the breaker but the heating light still comes on.

The heater shows 10 Ohms resistance and there is no voltage on the two 240V power supply terminals the heater plugs into when the heating light is lit. I tried to unplug the relay above the power supply terminals but I think all the relays are soldered to the board. Since the spa has been in constant operation, more or less, since 2005, I thought I should just replace the entire board. The spa is 240V, has one two speed pump and one single speed pump in addition to a 24 hour circulation pump. The heater has never been replaced so I hope that did not contribute to the relay failure. 

 

I'm planning on replacing the control board (part number 6600-088) with this part: Jacuzzi J-300 Collection Circuit Board 240v LED (hottubsupplystore.com)

But I wanted to check with the experts here to see if I'm overlooking something first. I'm impressed with the longevity of the original circuit board as the hot tub has spent it's entire life out doors in a PNW rainforest with no roof. 

[CanadianSpaTech]

Remove the relay board and have a look on the back for burnt relays

[Spasome]

On 1/18/2023 at 4:52 AM, CanadianSpaTech said:

Remove the relay board and have a look on the back for burnt relays

I decided to just order a new board, figuring even if I couldn't see burn marks on the PC board, the relay is probably bad anyway.