Refrigerant detection system with auxiliary control circuitry

1. A heating, ventilation, and/or air conditioning (HVAC) system, comprising:

auxiliary control circuitry configured to communicatively couple to a thermostat of the HVAC system, wherein the auxiliary control circuitry is configured to:

receive a control signal from the thermostat;

block subsequent transmission of the control signal to primary control circuitry separate from the auxiliary control circuitry in response to receipt of data indicative of a detected refrigerant external to a refrigerant circuit of the HVAC system;

in response to non-receipt of the data indicative of the detected refrigerant external to the refrigerant circuit, transmit, via a first connector port of the auxiliary control circuitry, the control signal to the primary control circuitry; and

in response to receipt of the data indicative of the detected refrigerant external to the refrigerant circuit, generate and transmit, via a second connector port of the auxiliary control circuitry, an alternative control signal, wherein the alternative control signal is configured to cause operation of a fan of the HVAC system.

2. The HVAC system of claim 1 , wherein the primary control circuitry is configured to operate the refrigerant circuit of the HVAC system and the fan of the HVAC system.

3. The HVAC system of claim 2 , comprising the primary control circuitry, wherein the primary control circuitry is a controller of an indoor unit of the HVAC system.

4. The HVAC system of claim 1 , comprising a motor of the fan of the HVAC system.

5. The HVAC system of claim 1 , wherein the auxiliary control circuitry comprises a third connector port configured to communicatively couple to a conventional thermostat and comprises a fourth connector port configured to communicatively couple to a communicating thermostat.

6. The HVAC system of claim 1 , wherein the control signal comprises a call for conditioning, and the call for conditioning is configured to initiate operation of a compressor of the HVAC system.

7. The HVAC system of claim 1 , wherein the auxiliary control circuitry is configured to transmit the alternative control signal to the primary control circuitry in response to receipt of the data indicative of the detected refrigerant external to the refrigerant circuit of the HVAC system, and the alternative control signal is configured to cause the primary control circuitry to output a notification indicative of a detection of refrigerant external to the refrigerant circuit.

8. A non-transitory computer-readable medium comprising instructions stored thereon, wherein the instructions, when executed by processing circuitry, are configured to cause the processing circuitry to:

receive a control signal from a thermostat of a heating, ventilation, and/or air conditioning (HVAC) system;

transmit, via a first connector port, the control signal received from the thermostat to primary control circuitry separate from the processing circuitry to enable operation of the HVAC system based on the control signal in response to non-receipt of data indicative of a refrigerant detected external to a refrigerant circuit of the HVAC system;

block transmission of the control signal received from the thermostat to the primary control circuitry to suspend an operation of the HVAC system in response to receipt of the data indicative of the refrigerant detected external to the refrigerant circuit; and

generate and transmit, via a second connector port, an alternative control signal in response to receipt of the data indicative of the refrigerant detected external to the refrigerant circuit to cause operation of a fan of the HVAC system.

9. The non-transitory computer-readable medium of claim 8 , wherein the additional alternative control signal comprises a series of pulsating control signals transmitted at a set frequency.

10. The non-transitory computer-readable medium of claim 8 , wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to selectively transmit the alternative control signal to a motor of the fan of the HVAC system and to primary control circuitry configured to operate the HVAC system.

11. The non-transitory computer-readable medium of claim 8 , wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to:

determine that the refrigerant external to the refrigerant circuit is no longer detected;

monitor a duration of time elapsed after the determination that the refrigerant external to the refrigerant circuit is no longer detected; and

block transmission of the alternative control signal in response to a determination that the duration of time exceeds a threshold period of time.

12. The non-transitory computer-readable medium of claim 8 , wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to receive the data indicative of the refrigerant detected external to the refrigerant circuit of the HVAC system from a sensor disposed within an air flow path of the HVAC system.

13. The non-transitory computer-readable medium of claim 8 , wherein the thermostat is a conventional thermostat or a communicating thermostat, and wherein the instructions, when executed by the processing circuitry, are configured to cause the processing circuitry to:

receive the control signal from the conventional thermostat via a third connector port; and

receive the control signal from the communicating thermostat via a fourth connector port.

14. A heating, ventilation, and/or air conditioning (HVAC) system, comprising:

a thermostat configured to transmit a control signal indicative of a call for conditioning; and

auxiliary control circuitry, comprising

a first connector port configured to communicatively couple to primary control circuitry configured to operate a refrigerant circuit of the HVAC system; and

a second connector port,

wherein the auxiliary control circuitry is configured to:

receive the control signal from the thermostat;

in response to non-receipt of data indicative of a detection of refrigerant external to the refrigerant circuit of the HVAC system, transmit, via the first connector port, the control signal received from the thermostat to the primary control circuitry separate from the auxiliary control circuitry to cause operation of the refrigerant circuit based on the control signal;

in response to receipt of the data indicative of the detection of refrigerant external to the refrigerant circuit, block transmission of the control signal received from the thermostat to the primary control circuitry via the first connector port; and

generate and transmit, via the second connector port, an alternative control signal to cause operation of a fan of the HVAC system in response to receipt of the data indicative of the detection of refrigerant external to the refrigerant circuit.

15. The HVAC system of claim 14 , comprising the primary control circuitry, wherein the primary control circuitry is configured to operate the refrigerant circuit based on the control signal.

16. The HVAC system of claim 15 , wherein the primary control circuitry is configured to:

receive the alternative control signal; and

operate the fan of the HVAC system in response to receipt of the alternative control signal.

17. The HVAC system of claim 14 , wherein

the second connector port is configured to communicatively couple to a motor of the fan of the HVAC system, and

the auxiliary control circuitry is configured to selectively transmit the alternative control signal to the primary control circuitry via the second connector port or to the motor of the fan via the second connector port in response to receipt of the data indicative of the detection of refrigerant external to the refrigerant circuit.

18. The HVAC system of claim 14 , wherein the thermostat is a communicating thermostat, and the auxiliary control circuitry comprises a third connector port configured to communicatively couple to a conventional thermostat.