Homeowner’s water company alerted them that there was a water loss of 7 per hour. After checking toilets, I searched the crawl space to find a moderately sized pinhole on the copper piping spraying water on the HVAC system. I cut and replaced a 10ft section of old copper piping with pex. Tested and checked for leaks. Explained to the homeowner about the condition of the existing water piping and recommended a full repipe.