I live in a condo and currently have two Honeywell T6575 thermostats. They are line voltage Fan Coil Thermostats. I need to replace both as one has a broken on/off switch and the other a dead LED screen. I ordered the newer version of Honeywell TB6575 Suitepro thinking this would be an easy swap. My older thermostat has nine wire leads the new one only seven. The grey wire (sw o/p) and Violet wire (fan com) don't have a place to go in the new thermostat. I've attached photos of the old and new setup. Any help on these??
Changing thermostats
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Terminal 6 where the purple wire is, is if your system uses end switches to run the fan only after the valve has open. Your new stat doesn't have that ability, so the purple wire is not used.
Terminal 5 is for a vent damper, new stat doesn't have ability to control that either, so its not used.
Terminal 5 is for a vent damper, new stat doesn't have ability to control that either, so its not used.
Thanks beenthere.
(Terminal 6) Currently the system runs the fan 100% of the time regardless of the compressor being on or off. I don't like it that it does that. I think the system designer oversized the units for my condo unit. They cool too quickly and this leads to a cold and clammy feeling. I read that running the fans 100% adds to this clammy feeling by making the room more humid, as the water on the condenser coils drys by re-humidifing the room. (I run separately a dehumidifier while running the a/c fan on slow.) I think turning the fans off might help when the compressor is off.
Re term 5 (vent damper) is this a problem that the stat can't control? Does it default to open or close? Why would they leave off this feature?
(Terminal 6) Currently the system runs the fan 100% of the time regardless of the compressor being on or off. I don't like it that it does that. I think the system designer oversized the units for my condo unit. They cool too quickly and this leads to a cold and clammy feeling. I read that running the fans 100% adds to this clammy feeling by making the room more humid, as the water on the condenser coils drys by re-humidifing the room. (I run separately a dehumidifier while running the a/c fan on slow.) I think turning the fans off might help when the compressor is off.
Re term 5 (vent damper) is this a problem that the stat can't control? Does it default to open or close? Why would they leave off this feature?
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Your vent should close without power to it.
Not every place has a fresh air vent, so its not included as an option with every thermostat.
Its possible your chilled water flow can be decreased to cause the system to run longer.
Yes, the fan on all the time can cause the water on teh coil to re-evaporate right after the chilled water valve closes. Plus, if the outside vent damper is open when the fan runs(usual set up), your pulling in more humidity the whole time.
Not every place has a fresh air vent, so its not included as an option with every thermostat.
Its possible your chilled water flow can be decreased to cause the system to run longer.
Yes, the fan on all the time can cause the water on teh coil to re-evaporate right after the chilled water valve closes. Plus, if the outside vent damper is open when the fan runs(usual set up), your pulling in more humidity the whole time.
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