Very little maintenance is required for solar water heating systems. You should occasionally check the system pressure, to make sure there has been no water loss, and to check for any air in the system. The only other requirement is to ensure that there is an electricity supply connected at all times, otherwise without pump circulation, in strong sunshine, the panel could overheat. Over heating is OK for a while but it can cause the glycol in the system to break down prematurely. The over heating can be a serious issue if you have not used flexible steel solar piping or copper pipe for the plumbing.