After installation and active use of the ersatzteilCHECK app, the depotCHECK app enables the availability of spare parts in the stored shopping cart to be displayed for defined wholesalers, provided they transmit the inventory data. Availability can also be checked in the Vaillant central warehouse.For organizational or time reasons, an express order can then be sent directly to a desired delivery address in an emergency.The use of the app by skilled craftsmen requires a known customer number at Vaillant Deutschland GmbH & Co. KG, Remscheid.