drallis01

Regarding the multi meter. I have one. Confirm test the 2 heater lugs and to test when the spa is calling for heat with the light solid and not flickering. The spa is 8 years new. I was thinking of just swapping out the whole control box/heating element. The Cal Spa site wants $750 for just the circuit board. I have found a few sites that sell the whole BP box/heater for around $540. I know I can do a complete swap just going 1 for 1 on the plugs and confirming the dip switches. For example here is a place that sells the whole unit for $567 https://www.hottuboutpost.com/cal-spas-pack-ele09002057-csbp501-csbp501x/ You are correct on the "slightly", I would not trust my skills to change a relay on the board.

I have a 2015 Cal Spa Platinum Series P-880b with a Balboa BP 501x control box. Heater is HTR 5.5KW Titanium M7. Top side is TP 600. No fault codes. TP 600 shows heat light on and steady (not flashing) Water wont heat and spa runs continuously. Temp stays at around 87 but is set to 100. Display is seat to Ready. I am slightly mechanically competent and contemplating just replacing the M7 heater tube or the entire BP 501x with the M7. Any suggestions? Replace the M7 or the whole box and M7