Sensors & controllers

54 products from $0 Pay in BTC, ETH or USDT

Flow sensors and meters, G1/4 temperature sensors, fan and pump controllers and their cables for custom loops, from Aqua Computer, EK, Alphacool and Barrow. Plan the connections first, and pay in BTC, ETH or USDT.

54 products

54 products

Products

Buying sensors & controllers at HodlChip

Sensors tell you what your loop is doing; controllers act on it. A useful setup has three parts:

  • Coolant temperature: a G1/4 inline or plug sensor, usually a 10k thermistor with a 2-pin plug. Fans that follow coolant temperature keep a loop much quieter than fans that follow the CPU.
  • Flow: mechanical indicators show that coolant is moving; electronic flow sensors report the flow rate and can raise an alarm or shut the PC down if the pump stops.
  • Controllers: run fan and pump curves from those sensors. Some work on their own; others connect to an internal USB header and are set up in the maker's software.

Check the connections before ordering: the sensor plug, the cable length to your controller, and whether your motherboard has a temperature sensor header (often labeled T_SENSOR). Brand systems such as Aqua Computer's use their own cables and data connections, which are listed here too. A 24-pin bridging plug lets the pump run on its own while you fill and leak-test. For the rest of the loop, see pumps, reservoirs & distro plates and loop tools & accessories.

Going deeper: Custom water cooling guide for beginners (2026)

Questions about sensors & controllers

Should fans follow coolant or CPU temperature?
Coolant temperature. It changes slowly and reflects the real heat load of the loop, so fan speeds stay steady and quiet. CPU temperature jumps within seconds, which makes fans ramp up and down for no cooling benefit.
Do I need a flow sensor?
It is not required, but it is a good safeguard: an electronic flow sensor can warn you or shut the system down if the pump fails or the loop blocks. A simple flow indicator at least shows at a glance that coolant is moving.
Will a temperature sensor work with my motherboard?
Most G1/4 sensors are 10k thermistors with a 2-pin plug, which suits the temperature sensor header found on many motherboards and fan controllers. Check that your board has one, and that the cable reaches, before ordering.