LED PANEL indicated that thermistat faulure, I have changed the thermistat with the correct part as suggested by Hayward. Now panel indicates LO, limit string open. How do I close the string or reset.

 

LO I think is low flow, is filter clean? Water circulating good?

 

Filter and flow are correct. The unit was working until Thermostat error message. I have changed thermostat, now the LO message.
I have checked the Limiter switch by removing jumper leades, no change on error message. Also, switch is tripping when engaged, I believe this is a protection response. I was thinking of changing the breaker in case of fault in the switch.

 

As suggested by Hayward customer support:
You would need to test each switch in the limit string to find out
the problem. The limit string runs on 24VAC so you are looking for
power going into a switch but not returning out.

I have corrected the problem....found the fault and replaced the switch, which had shorted..