caldera hawaiian no heat

[cars30]

hi i have a temp light flashing i did the filter check by takeing out and running .no difference.circulation pump is moveing water a steady flow comeing out return.pump seems to be running at a low speed but is pumping.not sure how fast pump should be running.i changed the pressure switch and a new cable .what i did notice is my temp display on controler is stuck at 50 degress and tub water from sun is at 80 degress does it sound like a temp sensor

[HotTubLover57]

Start by turning the power off and unplug the sensors from the circuit board and then plug them back in. That will ensure that the sensors are plugged in properly - eliminating this as a possible cause. Then turn the spa back on.