Can hydronic radiant heating systems transmit Legionella?

What are the chances of getting Legionella from open system of hydronic radiant heat where you get your house heating and drinking water from the same source?

The risk from hydronic heating is unknown, but we know of no cases of Legionnaires’ disease from such sources. However, one can contract Legionella from home water distribution systems and large building water systems. But the risk is extremely low and close to zero if you are not a cigarette smoker. And, if you were a smoker, I would quit smoking and not worry about the hydronic heat.