If you have a four pipe system, you have a separate cooling pipes and heating pipes. Depending on the condo management company, depending on the season there may or may not be water in one of the set of pipes. Also, most of those systems use multi-speed fans so you need to have a thermostat that supports L,M,H fan speeds. The water pipes have valves that open and close on demand. The cold water pipes are controlled by Y and the Hot water pipes are controlled by W. You will need Nest Learning thermostat if you indeed have multiple speed blower fan. Make sure your thermostat system uses low voltage controls. Use a volt meter and verify the voltage is 24V AC power +/- 4V.
AC Cooling Wizard
NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
