Water Heaters · Tankless Components
Flow Sensor (Tankless)
A device in tankless water heaters that detects when water is flowing through the unit, triggering the heating system to activate. Uses paddle wheel, turbine, or pressure differential technology. Critical for on-demand operation - unit will not heat without flow detection.
Common uses
Flow detection, system activation, on-demand operation
Common symptoms
- No heating
- Delayed activation
- Intermittent operation
- False activation
Common repairs
- Sensor cleaning
- Sensor replacement
- Calibration adjustment
Related terms
Pro launch updates
Get notified when Pro launches, plus a monthly code-change digest. Email only — no account required.