The thermostat displays E13 and cannot join Zigbee/Z-Wave or other smart home networks (for multi-protocol models).

Safety: No high-voltage work is required for network pairing, but turn off power if you remove the thermostat from the wall.

Steps to troubleshoot E13 (auxiliary radio error):

• 1. Confirm protocol: Verify that your Stelpro thermostat model supports the specific protocol (Zigbee, Z-Wave, etc.) you are trying to use.
• 2. Reset pairing: Put the thermostat into exclusion/reset mode as described in the manual, then attempt to re-include it on your smart home hub.
• 3. Move hub closer: Temporarily move your smart home hub within a few feet of the thermostat to ensure a strong signal during pairing.
• 4. Check hub compatibility: Confirm that your hub firmware supports the specific Stelpro model. Update the hub firmware if needed.
• 5. Reduce interference: Keep Wi-Fi routers, cordless phones, and other RF devices a few feet away from the thermostat and hub during pairing.
• 6. Power cycle: Turn the breaker OFF and ON to reboot the thermostat, then retry pairing.
• 7. Replace thermostat: If E13 persists and the thermostat cannot be discovered by any compatible hub, the auxiliary radio module may be defective, and the thermostat should be replaced.

Note: Some Stelpro models use a plug-in radio module; if accessible, reseat the module with power OFF.