Filling device for a pressurised heating circuit

A filling loop device for a pressurized heating system comprising:

• a casing having an inlet port connected by a fluid passage to an outlet port, said inlet port connectable to a fluid supply and said outlet port connectable to a heating system fluid circuit;
• a spool chamber interrupting said fluid passage, a spool slidably housed in the spool chamber, said spool including a through passage capable of communicating the inlet port and outlet port for fluid flow there between, and a drain passage capable of communicating the outlet port and a drain port formed in a lower part of the spool chamber, said drain port for discharge to a drain at ambient pressure, wherein water passing into either of the through passage or the drain passage cannot pass into the other of the passages;
• bias means to urge the spool so that the drain passage communicates the outlet port and the drain port and closes the inlet port;
• and
• an actuator operable to overcome the bias, whereby the filling loop device acts as a deadman valve and a fluid supply break ensuring that the pressurized heating circuit is normally isolated from the supply, and fluid in the heating circuit is normally isolated from the supply, and fluid in the heating circuit cannot leak back into the supply.