I read an earlier post that appears to be a similar problem to mine but not exact. I have an older no-name spa that heats up great but gets to a point where the pump is running but the light to the heater shuts off and the breaker has to be reset to get the heater to come back on. The filter is clean, the water level is high and the water appears to be circulating. Could the problem be the Hi Limits switch? Thanks in advance for your assistance with this.