drayton LP241 timer cutting out on baxi bermuda back boiler

[DavidN]

hi, got a drayton LP241 digital timer cutting out (powered up + disconnected from system, does not cut out) on
a baxi bermuda 552 back boiler system (2 honeywell values by tank) - as soon as you power it up, it cuts out .
(few hours earlier the system has lost hot water pressure ) help !