Display shows OH or OHH and spa shuts down with pumps off and heater disabled

Safety first: Turn off power at the GFCI breaker. Do not continue to run an overheating spa.

OH/OHH indicates the control system believes the water or heater area is too hot, usually above safe limits.

• Remove the cover: Open or remove the spa cover to allow heat to escape and let the water cool naturally.
• Check water level: Ensure the water level is above all suction fittings and at the recommended fill line. Low water can cause poor flow and localized overheating.
• Clean the filter: Remove the American Whirlpool filter cartridge(s) and rinse thoroughly with a garden hose from top to bottom. If the filter is old or heavily soiled, replace it.
• Verify all valves are open: In the equipment bay, confirm all slice valves or ball valves on the pump and heater plumbing are fully open.
• Bleed air from the system: Loosen the pump union on the circulation pump slightly until water seeps out, then retighten. This helps remove air locks that can stop flow through the heater.
• Restore power and test circulation: Turn the GFCI back on and run the circulation pump. You should see strong return flow in the spa. If flow is weak or intermittent, the circ pump or impeller may be failing.
• Monitor temperature: Allow the spa to run with the heater enabled and watch the temperature. If OH returns quickly and the water is not actually hot, the high-limit sensor or control board may be misreading.

If the spa truly overheats or the OH code persists after filter cleaning and air removal, contact a qualified technician to test the heater relay and sensor circuits.