Fan Coil Unit Thermostat Wiring

In the most basic system this functionality is provided by use of a fan center relay and the low voltage wiring to the thermostat now will require a minimum of three wires for heat only units and four wires for heat cool fan for control.

Fan coil unit thermostat wiring.

Enviro tech fan coil unit wiring diagram base website diagramofhumanheart associazionecicogna it replacing honeywell t651a tstat for condo system doityourself com community forums thermostat adapter bestco technology ltd module ceiling mount china best 7 day programmable electric replace modulating housing htw 31 f17 mlm controller rickardair how to wire an air conditioner control 5 wires easy. This additional terminal is labeled g in the thermostat. Here is the industry standard thermostat wire color code used for most systems. I have further analyzed the wiring between the fan coil units and thermostats and it definitely looks like temporary stuff.

I am especially concerned about possible confusion between the fancoil s c terminal fancoil to water control valve and y terminal thermostat to fancoil for water control valve. To install your unit you ll need to connect the correct wires to the terminals on the back of your new thermostat. This wire connects to your heat pump if applicable. If fan speeds are adjustable the relay board is producing 24 volts.

Verify fan speed will change from high medium and low by utilizing remote 3 speed switch thermostat or connecting by p18 to p15 p18 to p16 or p18 to p17.