You probably have a low pressure container (or a burst bag). a) switch off the waterworks (ektrelectrics´ - with a switch, circuit breaker) b) drop the water as close to the waterworks as possible, leave the tap open c) check the pressure in the waterworks tank with a manometer (somewhere it should have a ´autovalve´) d) if the pressure is lower than should be, blow it with the pump to the prescribed (depending on the type, usually 1.5-2 atm). e) if water flows out of the valve, the bag burst - and it needs to be replaced (it is better to call the service station) ;-)