What if I have to drain the system for major maintenance and repairs? October 14, 2021 By It is not often necessary or desirable to fully drain a system during maintenance operations. Individual radiators, or sections of the system can isolated for the majority of operations. Hydromx® is a valuable heat transfer solution with a long life expectancy and should be reused whenever possible. The solution can be drained and stored in suitable tanks (plastic collapsible tanks are recommended for large heating systems) and the system refilled again after the maintenance is completed. During this operation the concentration of Hydromx® should be checked and adjusted with additional Hydromx® where necessary in order to maintain the highest efficiency savings.