Instructions condensing Air heaters type HR
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7.5.2 T max. Flue gas outlet
For the application of plastic flue material on the HR heaters the maximum flue gas temperature
is monitored (Tflue < 120 °C). A temperature sensor in the flue outlet the heater monitors the
temperature of the flue. When the flue temperature is too high (Tflue > 110 °C), the burner
modulates its capacity to the minimum. When the temperature keeps rising, and reaches
115°C, the burner stops. When after an automatic restart the situation repeats itself the heater
will lock out. The error A7 will show in the display.
7.6 Flue Transport Supervision
The unit is provided with a pressure switch to control the transport of combustion air through the
heat exchanger. It checks in the pre purge phase if there is sufficient movement of combustion
air through the heat exchanger by measuring the pressure difference over the heat exchanger.
If the pressure difference is too low in the pre purge phase, default A9 will occur. This could
mean that combustion air is leaking from the heat exchanger and so the heat exchanger must
be checked on leakage.
7.7 Description heater control HC
The heater control HC controls the unit and communicates with the room thermostat.
Functions integrated in the heater control HC are:
-two wire communication with room thermostat
-spark igniting on burner
-ionisation flame guard on burner
-controlling the gas valve
-modulating the premixed fan and burner
-modulating the system fan
-guarding the temperature of the heat exchanger
-LED signals status of heater, heat demand: green, failure: red
-Status of heater on 8 segment display on heater control HC
-reset of heater
-service mode function
