What do I do when error code E:15 appears on the display?

Error code E:15 (shown as ":‚‰" on the display) indicates a water supply issue — the supply hose may be kinked, the water supply may be turned off, or the water supply line may be clogged. Check and straighten the supply hose, turn on the water supply, or unclog the water line to resolve the issue. (Page 41)