H2
Certikin
Inlet Water Temperature Sensor Fault / Low Temperature Lockout
Heater shows H2 and stops; may occur when pool is very cold or after long off periods.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Faulty inlet NTC sensor, Sensor not fully immersed in water stream, Wiring damage to sensor, Water temperature below minimum operating limit for Certikin heater
How to Fix / Troubleshooting
Safety first: Isolate power before accessing sensors.
- Check actual water temperature: Use a separate thermometer in the pool to confirm the real water temperature.
- Locate inlet sensor: Identify the inlet sensor on the heater manifold or pipework and ensure it is properly installed.
- Inspect cable: Look for physical damage or pulled cables, especially near cable glands.
- Warm-up strategy: If water is extremely cold, run the circulation system to mix and slightly warm the water before calling for heat again.
- Reset and test: Restore power and see if H2 clears. If not, the sensor may need replacement.
If the heater repeatedly shows H2 with normal water temperatures, have the sensor and control board tested.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Certikin inlet temperature sensor (NTC)
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements