PUK AutoPress pressurisation units are designed to replace water that has been lost through system leakage and to maintain the system design fill pressure in sealed heating and chilled water systems in accordance with BS7074. This reduces the air in your sealed system and consequently increases efficiency.
Most modern boiler and air conditioning systems are sealed and require a device to maintain the system pressure and warn of potential issues. These warnings include alarms for when the fill pressure is low or when the water has over-expanded causing too much pressure. All sealed heating systems need to have an interlock circuit so that the boilers are cut out if the unit is at fault.