MY HOT TUB ISN'T HEATING?
There can be several reasons why your hot tub isn't heating. Issues are primarily due to the heater element, pressure switch, flow sensor, pump, or computer board.
Heater element: If your heater element is burnt out or defective, the hot tub will not heat. In this case, the GFCI on the spa will trip, and you will not be able to reset it. This can be confirmed by disconnecting the heater element from the circuit board and removing the lead copper strips or wire. ( performed by a qualified electrician or service tech ). Reset the breaker; if it resets, you know that the heater element is defective. In that case, you have to change the heater element or the complete heater tube depending on the make and model of your hot tub.
- Heater elements burn out for various reasons, the most common being improper water chemistry, low pH and alkalinity, calcification caused by high minerals in the water, and low flow rates.
- If the GFCI still doesn't reset, the heater element is likely okay as it isn't connected and can't trip.
- Next is pressure sensors. Pressure sensors protect the hot tub by not allowing the heater element to turn on; you don't have enough water flowing over the heat core. If a pressure sensor is defective, you will have a FLO ERROR on your topside control. At this point, you would have an old-style pressure switch or temperature/pressure sensors on both sides of the heat core. It would help if you constantly changed both sensors.
- If your hot tub pump isn't running and the water is flowing, the pressure sensors are doing their job and not allowing the heater to activate. Check that your hot tub pump is running and the water is flowing. If so, you may require a new hot tub pump.
- If the heater element is fine, the pump is flowing water, and the pressure sensors are okay, then the last item is the circuit board. There is a fault with the circuit board, and a relay is stuck. If this is the issue, a new circuit board or a complete power pack is required.