The answer to 'tune-up leaking water' is that a leaking water issue during an HVAC tune-up is often caused by a clogged or faulty condensate drain line. This can lead to water backing up and leaking from the unit. Common symptoms include water pooling around the indoor unit, visible leaks, or water stains on the walls or ceiling.
The solution typically involves cleaning or unclogging the condensate drain line, which may require using a wet/dry vacuum or flushing the line with a vinegar solution. In some cases, the drain line may need to be replaced if it is severely clogged or damaged. For DIY homeowners, this is usually a relatively straightforward fix, but if the issue persists or you're not comfortable working on the HVAC system, it's best to call a professional HVAC technician to diagnose and resolve the problem.