Hot Springs Sovereign , No Heat With New Relay Board

[HottubBob]

My 2000 Sovereign has worked flawlessly until this year. I filled the spa in spring, turned on breakers and expected it to be ready the next day. But not this time. The water was still cold like it just came out of the garden hose. When I inspected the control board and relay board, I found the relay board had a obvious burned out relay. The board must have been on fire. Melted plastic above it and smoke scorched. The back of the relay board was covered in black. The center relay was fried and the other 2 relays the solder had melted away! This was a major melt down. However my jet and circulation pumps were still working fine. There were no flashing LEDs.

After installing a new style relay board, no heat still. Decided to replace heater and still no heat. Have been looking for similar posts but none found, hence this post. I did find some info for the new style relay board. There is a green LED and a red LED on the board near the top. My green is on but never have the red on. I am not sure what they indicate but assume the same as the 2 on the ICQ pcb.

I read a post that the red should be on. So I installed a second relay board and still the exact same conditions. The green and HEATER LED's on the main board are on. I also meter my old heater and found 37 ohms. One post on Youtube said 10 to 40 ohms is typical. Not sure the heater was bad but it is 15 years old.

I am puzzled, and would like some ideas to resolve this issue before buying a control board or main board.

Thank you

[Hot Spring Official]

Most newer replacement heaters will require a pressure switch bypass jumper (p/n 72768) be installed on the PCB where the previous pressure switch cable is plugged in.

[n1oty]

What is the voltage going to the heater??