Thermostat with carbon monoxide warning feature

• US 6,484,951 B1
• Filed: 04/15/2002
• Issued: 11/26/2002
• Est. Priority Date: 04/15/2002
• Status: Active Grant

• Current Assignee: Emerson Electric Company
• Original Assignee: Emerson Electric Company
• Inventors: Mueller, Carl J.
• Primary Examiner(s): Boles, Derek
• Application Number:
  US10/122,582
• Time in Patent Office: 225 Days
• Field of Search: 237/2.A, 237/12.3 C, 431/22, 431/16, 431/76, 126/116.A
• US Class Current: 237/2.00A
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G08B 21/14 Toxic gas alarms G08B21/16 takes precedence

Abstract

A thermostat comprising an audible alarm or LCD, and sensing means for sensing at least one signal from at least one external carbon monoxide detector. The thermostat is configured to change the temperature setting to 50° F., and to trigger the audible alarm or flash a warning on the LCD display when receiving a signal from at least one carbon monoxide detector indicating the presence of a harmful level of carbon monoxide. The heating system'"'"'s operation is not disabled but rather reduced to prevent potential freezing damage. The thermostat would continue the audible alarm, flashing warning and 50° F. temperature setting until it is reset.

Claims

1. A thermostat for controlling a gas-fired heating system for a space, comprising:

sensing means for sensing at least one signal from at least one carbon monoxide detector indicating a harmful level of carbon monoxide; and

control means responsive to said sensing means for lowering the thermostat set-point temperature to a predetermined temperature effective for preventing freezing of water pipes.

2. The thermostat according to claim 1, wherein the control means comprises a microprocessor having a software program for controlling the operation of said heating system.

3. The thermostat according to claim 1, wherein the predetermined minimal temperature for the space is approximately 50°

Fahrenheit.

4. The thermostat according to claim 2, further comprising an LCD display having a visible carbon monoxide warning, which is activated by said microprocessor upon sensing a harmful level of carbon monoxide.

5. The thermostat according to claim 2, further comprising an audible alarm, which is activated by said microprocessor upon sensing carbon monoxide.

6. The thermostat according to claim 2, wherein the sensing means comprises a high pass filter for isolating a high frequency signal from the wave form of an alternating current signal, to be input to said microprocessor.

7. The thermostat according to claim 2, wherein the sensing means comprises a microprocessor having a current sensing input pin.

8. A thermostat for controlling a gas-fired heating system for a space, comprising:

sensing means for sensing at least one signal from at least one carbon monoxide detector indicating a harmful level of carbon monoxide; and

a

microprocessor responsive to said sensing means for lowering the thermostat set-point temperature to a predetermined temperature effective for preventing freezing of water pipes, and

an LCD display controlled by said microprocessor, having a visible carbon monoxide warning that is activated by said microprocessor upon sensing a signal indicating a harmful level of carbon monoxide gas.

9. The thermostat according to claim 8, wherein the predetermined minimal temperature for the space is approximately 50°

Fahrenheit.

10. The thermostat according to claim 8, further comprising an audible alarm, which is activated by said microprocessor upon sensing carbon monoxide.

11. The thermostat according to claim 8, wherein the sensing means comprises a high pass filter for isolating a high frequency signal from the wave form of an alternating current signal, to be input to said microprocessor.

12. The thermostat according to claim 11, wherein the sensing means can sense a unique high frequency signal that indicates maintenance is required on the equipment sending the signal.

13. The thermostat according to claim 8, wherein the sensing means comprises a microprocessor having a current sensing input pin.

14. A method of operating a thermostat for controlling a heating system for a space having at least one carbon monoxide detector connected to the thermostat, the method comprising the steps of sensing a signal from at least one carbon monoxide detector indicating the presence of a harmful level of carbon monoxide gas, lowering the thermostat set-point temperature to a predetermined temperature effective for preventing freezing of water pipes, and activating an alarm.