COACH CO alarm

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The COACH Pro (CO alarm for boilers) ensures the security of equipment liable to produce carbon monoxide in the air. The COACH® alarm enables you to switch off a heater or boiler whenever they are thought to endanger the occupants of a house or flat. The COACH® alarm is equipped with the latest sensor and microprocessor technology guaranteeing precise measurements of CO levels ranging from 0 to 999ppm. It may be used for several years without any further adjustment. A patented algorithm enables us to simulate the level of CO effectively present in the blood, this is called the level of carboxyhaemoglobin or COHb. Click here for further information on COHb. It is possible to check the condition of the alarm at any time: how many times the alarm has been triggered, the highest levels registered and there is a signal in case of breakdown.
The COACH complies with the European standard (more about EN 50291) (Learn more).

Units and standards

CO molecule

The results of the analysis are given in ppm (parts per million) units of concentration. Using this measurement the calculator will calculate the theoretical levels of of COHb. If this measurement exceeds the thresholds given by the EN50291 norm, the alarm will be triggered off.

In an industrial environment, French regulations limit the concentration to 50 ppm for an 8 hour workshift. This is explained in an NIRS (National Institute für Research and Safety) document ND 1945-153-93. The installation of a COACH® alarm, which has a higher degree of accuracy ensures compliance with this regulation.


  • MAX: The maximum concentration is measured and memorised. The ’MAX’ key indicates this measurement and "MAX RESET" reinitializes it.
  • ALARM: Equipment which is likely to produce CO is cut off by means of a relay. This safety measure is accompanied by a loud alarm and a flashing light. Once the information has been acknowledged by pressing a key, the light will stop flashing but will remain switched on. The alarm then calculates the lapse of time necessary for the natural evacuation from the lungs of CO accumulated in the blood when concentration is inferior to 50 ppm.