Warmup strongly recommends that the relay is installed in a separate single gang box to avoid overheating and interference of other cables. Check with your electrician and refer to your local code for specific installation requirements.
This Relay-25 fits in a standard single gang box. It is used in conjunction with the 4iE® Smart thermostat series as well as the Tempo thermostat, in order to expand the original 15 amp capacity. It is specifically designed for large applications beyond 800 sqft.