HK 50 M – HK 10M – HK 100S SERVICE BULLETIN1.7.5 Flow and Return NTC probesWith the sensors, the temperature measurements on the flow and return lines of the combustion unit areread on the electronic card.(Figure 1.8)1.7.6 Safety thermostatThe safety thermostat can be set again manually. It's on the flow line. It is activated when water flowtemperature is 90OC and closes the burner. (Figure 1.9)1.7.7. Flue probeIt is under the heat exchanger. It is activated when the waste gas temperature exceeds 80oC and closes theburner. (Figure 1.10)Service Administration 9 03/2010
