- Tech found condenser not running when thermostat calls for heat. Found DATS on zone board reading 168°F with no heat strips or compressor running. Removed DATS and submerged in cold water; still reading 171°F, indicating DATS failure. - Advised customer and provided replacement quote. Customer opted to postpone replacing the DATS at this time. - Tech reprogrammed zone board and removed the DATS from the circuit to bypass its function. - Tested heat strips and defrost cycle. - Customer registered for a 1 system PSA with annual payment. System is operating normally at this time. Thermostat set to 70°F at tech departure per customer.