Non-electronic methods and apparatus for detecting wash pump cavitation in a dishwasher

1. A method for operating a dishwasher system using a cavitation sense fill system, the method comprising:

monitoring an output pressure of at least one recirculation pump in the dishwasher system; and

deactivating at least one fill valve in the dishwasher system when the output pressure satisfies at least one predefined criterion,

wherein the output pressure is monitored using a pressure wave damper, the pressure wave damper comprising tubing connected at a first end to an output of the at least one recirculation pump and at a second end to the cavitation sense fill system, the tubing having at least one loop therein.

2. The method of claim 1 , wherein the at least one predefined criterion comprises a minimum threshold pressure.

3. The method of claim 2 , wherein the minimum threshold pressure is 5 pounds per square inch.

4. The method of claim 1 , wherein the at least one predefined criterion comprises a minimum threshold pressure being maintained for a minimum time interval.

5. The method of claim 4 , wherein the minimum time interval is 2 seconds.

6. The method of claim 1 , further comprising the step of detecting a time-out condition for the at least one fill valve.

7. The method of claim 1 , further comprising the step of activating the at least one fill valve at a first predefined time and activating the at least one recirculation pump at a second predefined time.

8. The method of claim 7 , wherein a duration of time between the first predefined time and the second predefined time is between 50 and 60 seconds.

9. The method of claim 1 , further comprising the step of stabilizing said output pressure using a pressure wave damper.

10. A method for filling a dishwasher using a cavitation sense fill system, the method comprising:

activating a fill valve to turn on a water supply to the dishwasher;

starting a recirculation pump;

monitoring an output pressure of the recirculation pump using the cavitation sense fill system, the cavitation sense fill system being connected to an output of the recirculation pump through a pressure wave damper; and

deactivating the fill valve when the output pressure satisfies at least one predefined criterion,

wherein the pressure wave damper comprises a loop of tube connected at a first end to the output of the recirculation pump and at a second end to the cavitation sense fill system.

11. The method of claim 10 , wherein the at least one predefined criterion comprises a minimum threshold pressure.

12. The method of claim 11 , wherein the minimum threshold pressure is 5 pounds per square inch.

13. The method of claim 10 , wherein the at least one predefined criterion comprises a minimum threshold pressure being maintained for a minimum time interval.

14. The method of claim 13 , wherein the minimum time interval is 2 seconds.

15. The method of claim 10 , further comprising the step of detecting a time-out condition for the fill valve.

16. The method of claim 15 , wherein the time-out condition occurs when the fill valve has been open for 75 seconds.

17. The method of claim 10 , further comprising the step of activating the fill valve at a first predefined time and activating the recirculation pump at a second predefined time.

18. The method of claim 17 , wherein a duration of time between the first predefined time and the second predefined time is between 50 and 60 seconds.

19. The method of claim 10 , further comprising the step of stabilizing said output pressure using a pressure wave damper.

20. A method for filling a dishwasher using a cavitation sense fill system, the method comprising:

activating a fill valve to turn on a water supply to the dishwasher;

starting a recirculation pump;

monitoring an output pressure of the recirculation pump using the cavitation sense fill system, the cavitation sense fill system being connected to an output of the recirculation pump through a pressure wave damper; and

deactivating the fill valve when the output pressure satisfies at least one predefined criterion,

wherein the at least one predefined criterion comprises a minimum threshold pressure being maintained for a minimum time interval of 2 seconds.