F.75 isn't as stated below, 'a lack of water in system'.
It's either the pump isn't pumping, or more likely the central heating sensor isn't detecting pump water movement. This is often due to debris in the system collecting in the sensor, either clean out the sensor or replace it.
Carefree
January 2012
F75 no water in system ,fill water via filling loop to1.2bar take air from rad air vent,filling loop under boiler 831 has build in filling loop two nob ,press restart nob flam cross sign
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