I HAVE A VAILLANT THERMOCOMPACT BOILER AND THE PRESSURE GAUGE IS ZERO. CAN YOU TELL ME WHAT VALVE I HAVE TO TURN TO BRING THE PRESSURE BACK UP TO THE CORRECT LEVEL. THE BOILER WILL NOT START AND I BELIEVE THE PRESSURE IS THE MAIN PROBLEM.
There will be vavle at the bottom of the bolier and a lever to turn the valve is also provided with your boiler. Turn it right 90 degrees and you will hear water running and the pressure gauge moving up. when the pressure gauge reaches nearly 2 stop the valve.