Boilermate 2000 pump constantly running

I have a boilermate 2000 and the other day noticed the pump is constantly running and circulating stored water through the boiler (Baxi solo 3) all 3 pumps are set to maximum speed setting and boiler thermostat on full. Of the 3 LEDs the bottom 2 a constantly lit, top one lights when room thermostat clicks on. I have no problems with hot water from taps or radiators being cold. The stored temp readout on the display last night was 72 degrees (which I would of thought is plenty to shut off) yet keeps running and demanding more heat. I have viewed a few threads regarding this problem and looks like I have a pcb fault. Just wanted to double check before I fork out for a new one. Is there a way to single out the fault being a thermal sensor telling the pcb the stored water is cooler than actual or is 72 degrees plenty to shut down? Any help would be appreciated.

Thanks.

Check fault codes.
And check store sensor.
Check boiler pump and that unit is full.
All been covered on here.
Mike