How do I reset OH error flashing on display? I have replace Temp. sensor assy. everything works pumps, jets and lights when manually override on main board

You replaced the temp sensor, but did you replace the high limit sensor at the same time?

Anyway, turn the tub off (remove power) for about 15 seconds and turn it back on again.

i have a balboa 96md refilled water heats up to 91 then oh blinks on and off every thing shuts off temp display looks fine reads temp while heating up . would the heater be going out /