Air Sensing Thermostat AT-A

The AT-A is a simple air sensing ON/OFF capillary thermostat, with an adjustable range of 0-40ºC.

Air sensing capillary thermostat for freeze protection of heat tracing circuits in safe area applications

  • GRP weatherproof enclosure.
  • Liquid filled stainless steel sensor.
  • Adjustable temperature setting 0-40°C.
  • 16 amp switching capacity.
  • Available for 110/120V and 220/240VAC.
  • Suitable for all types of heating cables.


  • AT-A thermostats are temperature adjustable ONOFF thermostats utilising a liquid filled sensing bulb connected to an electrical switch via a capillary tube.
  • Expansion of the liquid on rise in temperature causes the switch to open and on cooling, it closes.
  • AT-A thermostats are designed to sense the ambient temperature to control heat tracing systems for frost protection applications.
  • The AT-A enclosure comes complete with 2 entries to suit 20mm glands. One for the power cable entry, the other for the heating cable.
  • The unit may be used in conjunction with a contactor, or other switching device, when controlling loads in excess of 16 amps.


  • Pipe mounting bracket - PB/S
  • Pipe fixing straps - PFS (specify required pipe diameter)

Product examples