
HVAC System Compatibility
Information
The EMS Si is designed to operate with low-
voltage heating and cooling systems. It is not
designed for use with line-voltage or millivolt
heating and cooling systems.
The EMS Si supports:
Up to 2 heat and 2 cool stages on a
conventional system.
Up to 3 heat and 2 cool stages on a heat
pump system.
The ecobee EMS Si supports the following
equipment:
Equipment
Supported?
Gas/Oil/Electric heating
Yes
(up to two stages)
Heat pump with auxiliary heat
Yes
(up to three stages)
Geothermal Heat Pump
Yes
Dual fuel systems
Yes
Standard electric cooling
Yes
(up to two stages)
Boilers Yes
Sensors with dry contact outputs
Yes
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