Today the Lennox system that cools the rental office had a slight low charge. I performed a leak search and discovered that the equalizing tube for the thermal expansion valve would set off the leak detector intermittently. This was reported to James and options were presented. The area of the leak was tightened and the refrigerant charge was adjusted. The system returned to proper function and was checked after the it was back in operation. Due to rain I did offer to return for a thorough leak search to confirm that there are no other leaks. This was declined at this time and James will contact us if it exhibits diminished cooling performance. Thank you, Jon Tech notes: Lennox condenser, s/m 1917F22993, AHU 1717C23079