Mr. Eamonn Smyth:

With regard to stagnation in the particular system that the petition showed, it is connected from the actual house storage. As I described to Deputy Kitt, it should not be connected like that. It should be connected from its own expansion tanks. If one gets any backflow one will go back into a system that only circulates within the heating system and not back into house water that can, potentially, come out of taps. The system should not be connected like that at all, and that is in the event there is backflow.

With regard to the stagnation issue, it is always recommended that any connection is done using a very short length of pipe so there is no amount of water within it that would stagnate. Stagnant water when heated can lead to stomach aches. The petitioner raised the issue of stagnant water occurring in the hotpress where the temperature might rise above 20° Celsius and start to grow Legionella bacteria, and I agree that is always possible. As I said to Deputy Kitt, once such water goes into the system it will be heated to above 60° Celsius thus killing Legionella within seconds. In most cases there is no risk. I agree with the petitioner that such a situation should not happen. It is a short way of feeding the system which should be fed from a separate tank and not from the domestic supply at all. In general, all of the issues that have been raised are down to poor workmanship rather than poor standards or requirements. Poor workmanship has been involved in all of the issues.