No cool downstairs. Nest Thermostat was indicating it could not operate the equipment install. I found a short on the contactor outside. Removed and replaced with new 1.5 pole contactor. System came on and operating properly at this time. New thermostat was not needed. Advise clients that our office check the warranty status of the equipment and it is only good for 5 years. Contractor did not register equipment within 90 days. System is operating properly at this time.