boiler keeps loosing pressure and I constantly have to refill every time I SWITCH off the heating sysytem,also there is no hot water when the boiler looses complete pressure, the overflow pipe outside has got a continious trickle of water
the expansion vessell in your boiler has lost pressure or the diaphram inside the vessell has developed a split the water trickling from the safety relief pipe outside is because as the hot water in the heating expands there is nowhere for the pressure build up to go to so the safety valve lifts and the water discharges outside when everything cools down the pressure gauge will read zero
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.