0 Pump overrun of CH After the end of CH operation the pump continues to run. The running time is factory set at the value in accordance with § 10.3. This setting can be changed. In addition, the pump runs automatically for 10 seconds once every 24 hours in order to prevent seizing. This automatic switching on of the pump occurs at the time of the last call for heat. To change the time, the room thermostat setting should be increased briefly at the desired time. 1 Boiler shutdown when required temperature reached The boiler controller can temporarily shut down the request for heat. The burner is then stopped. Shutdown occurs because the requested temperature has been reached.
When the temperature has fallen sufficiently and the anti cycle time has passed the shutdown is cancelled. 2 Self-test The connected sensors are checked regularly by the boiler controller. During the check the boiler controller does not perform any other tasks. 3 Ventilation When the appliance is started the fan is first brought to starting speed. When the starting speed has been reached the burner is lit. Code 3 is also visible when post- ventilation is taking place after the burner has stopped. 4 Ignition When the fan has reached the starting speed, the burner is ignited by means of electrical sparks. During ignition the code 4 is visible.
If the burner does not ignite, a new ignition attempt occurs after approximately 15 seconds. If after 4 ignition attempts the burner is not yet burning, the boiler controller goes into fault mode (See § 11.1). 5 CH operation An on/off thermostat, an OpenTherm thermostat, an external sensor or a combination of the latter can be connected to the boiler controller. When a request for heat is received from a thermostat, the fan is started (code 3 ), followed by ignition (code 4 ) and CH operating mode (code 5 ). During CH operation the fan speed and hence the appliance power are controlled by the boiler controller so that the CH water temperature reaches the desired CH supply temperature.
If an on/off thermostat is connected, this is the CH supply temperature set on the display. In the case of an OpenTherm thermostat the desired CH supply temperature is determined by the thermostat. In the case of an external sensor the desired CH suppply temperature is determined by the heating line programmed in the boiler controller. For the latter two, however, the maximum is the temperature set on the display. During CH operation the requested CH supply temperature is indicated on the operating panel. The CH supply temperature is set to 75°C and can be adjusted between 30°C and 80°C. If, under circomstanses a flow temperature is needed up to 90°C the value of parameter 5 . (max.
value for flow temperature in display) needs to be adjusted. When the DHW comfort function is switched on (See code 7 ) any OpenTherm request for heat of less than the value of par. E is ignored. 6 DHW operation The hot water supply takes priority over the heating. If the flow switch detects a need for more than 2 l/min of DHW, any demand for CH will be interrupted. After the fan has reached speed code 3 and ignition has taken place code 4 the boiler controller goes to DHW mode code 6 . During DHW operation the fan speed, and hence the power of the appliance, are controlled by the boiler controller so that the DHW water temperature reaches the DHW temperature setting.
The water temperature can be set between 40°C and 65°C (See § 10.1.6). Intergas Heating Ltd 13