3iE Energy-Monitoring Thermostat

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Installing a relay

Each relay will need its own dedicated 20A circuit.

When you have multiple floor heating systems being powered that require more than 15amps, you can use an additional 3iE as a relay as opposed to purchasing a separate generic relay which Warmup can supply.

Remember that each 3IE can only handle a max of 15 amps, so if your floor heating system configuration goes beyond a total of 30amps, please contact us for other options. The second 3IE would be programmed as a “relay” to the primary thermostat which will serve as the “master” control –

See the programming section of the Warmupedia for instructions or pg. 16 of the programming manual on our website for directions.


Each thermostat/relay can handle a maximum of 15 amps. The relay will turn on and off in conjunction with the “Master” thermostat.


Two conductor wires go from terminals 2 & 3 from master relay to terminals 2 & 3 of relay (slave) thermostat.


3IE Installingrelay