Honeywell THX9421 Thermostat User Manual


 
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ 2.0 WITH EIM
123 68-0311—01
Zoning FAQs
Q: How does the Prestige or Prestige IAQ thermostat control a humidifier in zoned systems?
A: If ISU 8070 Humidification Control is set to Humidify on Demand: Thermostat Controls Fan, then the zone panel will close the
dampers for the other zones with a call for humidification.
If ISU 8070 Humidification Control is set to Humidify on Demand: Humidifier Controls Fan, then all dampers will be open with a
call for humidification (unless another zone is calling for heat, cool or fan at that time).
See Fig. 245.
Q: How does the Prestige or Prestige IAQ thermostat control a ventilator in zoned systems?
A: If ISU 10060 Ventilation Fan Control is set to Thermostat Controls Fan, then the zone panel will close the dampers for the other
zones with a call for ventilation.
If ISU 10060 Ventilation Fan Control is set to Equipment Controls Fan, then all dampers will be open with a call for ventilation
(unless another zone is calling for heat, cool or fan at that time).
See Fig. 246.
Q: How does the Prestige or Prestige IAQ thermostat control a dehumidifier in zoned systems?
A: If ISU 9130 Dehumidifier Fan Control is set to Thermostat Controls Fan, then the zone panel will close the dampers for the
other zones with a call for dehumidification.
If ISU 9130 Dehumidifier Fan Control is set to Equipment Controls Fan, then all dampers will be open with a call for
dehumidification (unless another zone is calling for heat, cool or fan at that time).
See Fig. 247.
Q: Will the 2-wire Prestige IAQ thermostat work with a zone panel?
A: It depends on the zone panel:
HZ322 or HZ432 (without an add-a-zone): If you have an HZ322 or HZ432 on a 2-4 zone system and you are not going to
control a humidifier, dehumidifier, or ventilator with the thermostat, you can use a THM4000R1000 wireless adapter with the
zone panel and connect the 2-wire Prestige IAQ thermostat as one of the zones. A single THM4000R1000 wireless adapter
allows you to connect up to three 2-wire Prestige IAQ thermostats or wireless FocusPRO thermostats with an HZ322 or up
to four 2-wire Prestige IAQ thermostats or wireless FocusPRO thermostats with an HZ432.
HZ432 (with a TAZ-4 add-a-zone): You cannot use a wireless adapter when a TAZ-4 is used. Each 2-wire Prestige IAQ
thermostat used would need a separate THM5421R Equipment Interface Module. The equipment interface module would
wire to the zone it is controlling on the HZ432 or TAZ-4.
Zone panel with no master or slave: As long as all zones on the zone panel are wired the same and they use typical
terminals with an R and C plus Y, G, etc, the 2-wire Prestige IAQ thermostat should work. Each 2-wire Prestige IAQ
thermostat used would need a separate THM5421R Equipment Interface Module. The equipment interface module would
wire to the zone it is controlling on the zone panel.
Master zone: A master uses separate O and B wires. The 2-wire Prestige IAQ thermostat cannot be used as a master
thermostat.
Q: Can I use the remote indoor sensors with the Prestige IAQ if I have zoning?
A: It depends. The Prestige or Prestige IAQ can only control 1 zone, even if it is used with multiple sensors. The Prestige or
Prestige IAQ cannot be used with a remote sensor if it is used with a THM4000R adapter. The 2-wire Prestige IAQ thermostat
can be used with a remote sensor if it is used with a THM5421R Equipment Interface Module or if the Prestige is wired directly
to the panel.
Q: Can I set up Delta T Diagnostics on a zoned system?
A: No. Delta T Diagnostics control uses supply and return sensors to measure the difference between the supply and return
temperature and verify the system is operating correctly. This feature can not be used if the thermostat is set up for zoning
because Delta T is affected by the position of the dampers and you may have one zone running heat while another zone is
calling for cool (and vice versa).
Q: Can I use a telephone access module with the 2-wire Prestige IAQ thermostat?
A: No. The telephone access module only works with the TH9421C or TH5320C communicating thermostats and the EIM or
zone panel used with those controls. See the Gateway section for information on using Prestige IAQ with a THM6000R
Gateway for Internet access.