Pump cycle Vaillant

[K.D.B Heating]

On the vaillant ecotec plus's under the installer level and program checks there is an 7.5 min programme called pump cycling which you can runderstand on your hot water or heating circuit I know what it dose ect ect bleeding the system of the air.
The reall qestion is how dose it work just a curious engeineer if anyone could she'd some light please go ahead!
Thanks.

 

[Chalked]

Exactly as you said. It clears air from the boiler heat exchanger ( not your system) it opens the diverter valve ( combi) to clear any residual air from that too. The pump, turns on and off a few times to let the air rise to the auto air vent built into the boiler.

As I said it will not clear air from your entire system.