Error Code
COOL error code — Hot Spring / Watkins spa
Always cut power at the breaker before opening the spa pack or touching wiring. Spa equipment runs at 120/240V and can be lethal. If you are unsure, hire a licensed spa technician.
COOL is the no-heat code: water 20°F under target. The heater element is the usual suspect on systems this age, with the relay and hi-limit close behind. It also shows during recovery after a refill — give a cold fill time before diagnosing.
What COOL means
Water 20°F or more below set point.
Diagnose in order
- Confirm the heater is getting a call for heat and power
- Test the heater element for continuity — the most common COOL cause
- Test the hi-limit sensor and heater relay
- Rule out massive heat loss (cover condition, winter winds)
Likely failed parts
Frequently asked questions
Related codes & guides
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