A control system may include a thermostat device and boiler control device. The thermostat device may be configured to receive electrical power from second wiring terminals and provide control signals to boiler control device using a second radio when wires are not present in first wiring terminals. The thermostat device may also be configured to receive electrical power from the first wiring terminals and provide the coded control signals to the boiler control device through the first wiring terminals when wires are present in the first wiring terminals. The boiler control device may be configured to receive the control signals from the thermostat device using a third radio and selectively couple the third wiring terminals to fifth wiring terminals to selectively control activation of the boiler-based heating system when wires are not present in fourth wiring terminals.