Balboa 700 Series Sensor Kit, 30337

The Balboa 30337 is the dual sensor assembly for 700 series systems. It supplies both sensors the control needs, the hi-limit and the temperature sensor, in one kit.

What each sensor does

The temperature sensor is what the control reads to decide whether to call for heat, and it is the one that gives you a display reading. The hi-limit is a safety device. Its job is to shut the heater down if the water gets too hot, regardless of what the temperature sensor is reporting. They are different components with different failure symptoms, but they live in the same place and are replaced through the same access.

Sizes and lengths

The hi-limit sensor has a 1/4 inch diameter bulb on a 31 inch cable. The temperature sensor has a 3/8 inch diameter bulb on a 96 inch cable and finishes in a 4 pin white end connector. Compare those against what is in your spa before ordering.

Cross references

This sensor kit turns up under a number of part numbers depending on where it was bought, including 340202DK, 34-0202D-K, 10283 and 9711-27. If the number on your old assembly is one of those, this is the same kit.