This is one of the most common questions we answer to our customers on the phone or when they call into the shop. You will find that if your Worcester boiler falls below 1 Bar pressure the boiler should cut out as a safety feature. You will now need your key. Insert the key into the charging link at the bottom of the boiler and turn. Raise the pressure to 1 Bar only and not anymore. This simple procedure should be carried out when the heating is off and also cold. Remember that it should only be required to do this maybe once a year. If you keep losing boiler pressure it means you have a leak which will require a professional repair. Clickonboilerspares sell a dual key pack to fit all Worcester boilers. When your boiler is back to 1 Bar remove the key and your boiler should now operate. It is important that if you find your boiler is persistently losing pressure you get it fixed as adding water to a heating system too often can cause scale problems.