Display shows OHt or HOT, spa shuts down heater and may run pumps to cool.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Scale buildup in heater, Restricted flow at heater inlet/outlet, Failing circulation pump, High limit sensor reading localized hot spot

Safety: Turn off power and allow the spa to cool before working on the heater.

Clean filter and check flow: Ensure maximum flow through the heater by cleaning or replacing the filter and verifying pump operation.
Inspect heater unions: Check for partially closed slice valves or kinked hoses near the heater.
Descale heater (advanced): If you have hard water and repeated OHt errors, a technician can remove and descale the heater tube.
Replace circ pump if weak: If flow is poor even with a clean filter, replace the circulation pump.

Hard 4/5

Heater Assembly

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