Hi guys I've got a potterton gold combo boiler and just recently when the water temp is set just above the minimum level it cuts out? Central heating is fine but when I set the water temperatre slightly above minimum I can hear a rumbling from the boiler and then I lose hot water. If I keep the hot water on minimum it does heat up and stays quite warm but as soon as I increase it past a certain level it rumbles then I lose hot water. Any ideas???
Thanks in advance
Thanks in advance