Homes and condominiums with hot water (radiant) heating systems have potential leak & health issues. Certain types of PEX B tubing used in these systems have a high failure rates. Identifying the tubing type can be difficult.  In addition if the water heater is used both for heating and bathing unhealthy bacteria may be able grow in within the potable water lines. Depending the type and method used for the installation of the heating lines,  water if not circulated,  is prone to developing bacteria during the summer months.