Viessmann, a German manufacturer of heating and cooling systems, has issues a voluntary recall for its Vitodens 200-W and Vitodens 222-F series boilers used for space or domestic water heating. According to the recall, the systems have a heat excahnger back plate that can "corrode and leak flue gasses, allowing the boiler to emit excessive amounts of carbon monoxide, posing a CO poisoning hazard to consumers."
There are five affected models in a specific serial number range (see above), and no injuries have been reported so far.