Boiler control methods

1. A method for controlling a boiler configured to provide a heated boiler fluid for heating a space of a building that is to be temperature controlled by the boiler, wherein the boiler including a burner, the method comprising:

receiving a call for heat that is based on an air temperature sensed in the space of the building;

firing the burner based on the call for heat;

with the burner firing, monitoring over time a temperature deviation between a temperature of the boiler fluid of the boiler and a heating temperature profile, and if the temperature deviation exceeds an allowable deviation, shutting off the burner; and

wherein the heating temperature profile represents an expected temperature response of the temperature of the boiler fluid over time to the burner firing; and

subsequent to shutting off the burner, monitoring the temperature of the boiler fluid over time.

2. The method of claim 1 , further comprising:

subsequent to shutting off the burner:

determining if the temperature of the boiler fluid decreases faster than a predetermined rate;

if the temperature of the boiler fluid decreases faster than the predetermined rate:

modifying the heating temperature profile; and

returning the boiler to a ready state, wherein in the ready state, the burner is allowed to fire based on the call for heat or a subsequent call for heat.

3. The method of claim 2 , wherein the heating temperature profile includes a maximum temperature rise slew rate, and the step of modifying the heating temperature profile including increasing the maximum temperature rise slew rate.

4. The method of claim 1 , further comprising:

subsequent to shutting off the burner:

determining if the temperature of the boiler fluid decreases faster than a predetermined rate; and

if the temperature of the boiler fluid does not decrease faster than the predetermined rate, disabling the boiler.

5. The method of claim 4 , further comprising:

subsequent to disabling the boiler, re-enabling the boiler after the temperature of the boiler fluid decreases below a limit.

6. The method of claim 1 , wherein if the temperature deviation does not exceed the allowable deviation, the method further comprises modifying the heating temperature profile based upon at least one actual measured temperature rise profile of the temperature of the boiler fluid.

7. The method of claim 6 , wherein the heating temperature profile includes a maximum temperature rise slew rate, and the step of modifying the heating temperature profile includes decreasing the maximum temperature rise slew rate based upon a measured slew rate of at least one actual measured temperature rise profile of the temperature of the boiler fluid.

8. The method of claim 1 , further comprising:

measuring a boiler temperature rise delay between when the burner was fired and when a selected temperature rise in the temperature of the boiler fluid is detected; and

modifying the heating temperature profile based upon the boiler temperature rise delay.

9. The method of claim 8 , wherein if the boiler temperature rise delay exceeds a predetermined maximum delay, shutting off the burner.

10. The method of claim 9 , further comprising:

subsequent to shutting off the burner:

determining if the temperature of the boiler fluid decreases faster than a predetermined rate; and

if the temperature of the boiler fluid decreases faster than the predetermined rate:

modifying the heating temperature profile; and

returning the boiler to a ready state, wherein in the ready state, the burner is allowed to fire based on the call for heat or a subsequent call for heat.

11. The method of claim 1 , wherein the temperature of the boiler fluid is measured proximate a water outlet of the boiler.

12. The method of claim 11 , wherein the temperature of the boiler fluid is measured by a sensor in thermal communication with a water outlet pipe of the boiler.

13. The method of claim 1 , wherein the temperature of the boiler fluid is measured via an Aquastat.

14. A method for controlling a boiler configured to provide a heated boiler fluid for heating a space of a building that is to be temperature controlled by the boiler, wherein the boiler including a burner, the method comprising:

receiving a call for heat that is based on an air temperature sensed in the space of the building;

firing the burner based on the call for heat;

while firing the burner, monitoring over time a temperature difference between a first boiler temperature and a second boiler temperature, the first and second boiler temperatures being monitored by sensors at different boiler locations, and if the temperature difference exceeds a selected difference, shutting off the burner, wherein the first and second boiler temperatures are indicative of temperatures of the boiler fluid at different boiler locations; and

monitoring a temperature deviation between the first boiler temperature and a heating temperature profile that represents an expected temperature response of the first boiler temperature over time to the burner firing, and if the temperature deviation exceeds an allowable deviation, shutting off the burner.

15. The method of claim 14 , wherein the first boiler temperature is measured proximate a water outlet of the boiler and the second boiler temperature is measured proximate a domestic hot water coil.

16. The method of claim 14 , wherein the first boiler temperature is measured proximate a water outlet of the boiler and the second boiler temperature is measured proximate a water return of the boiler, and further comprising modifying the heating temperature profile based upon the difference between the first and second boiler temperatures.

17. A boiler system configured to provide a heated boiler fluid for heating a space of a building that is to be temperature controlled by the boiler, the system comprising:

a boiler that includes a burner;

a thermostat disposed in the space of the building to provide one or more calls for heat to regulate the temperature in the space of the building;

a sensor for sensing a boiler temperature indicative of a temperature of the boiler fluid;

a controller for controlling firing of the burner based on the one or more calls for heat from the thermostat, the controller configured to compare over time the boiler temperature with a heating temperature profile, and to shut off the burner if a temperature deviation between the boiler temperature and the heating temperature profile exceeds an allowable deviation and to monitor the temperature of the boiler fluid over time subsequent to shutting off the burner; and

wherein the heating temperature profile reflects an expected temperature response of the boiler temperature over time with the burner firing.

18. The boiler system of claim 17 , wherein the controller is further configured to store a boiler performance history, and to dynamically modify the heating temperature profile based upon the stored boiler performance history.

19. The boiler system of claim 17 , wherein the controller is further configured to dynamically modify the allowable deviation over time.

20. The method of claim 1 , wherein the heating temperature profile further describes an expected temperature response of the boiler temperature over time with the burner not firing.

21. A method for controlling a boiler configured to provide a heated boiler fluid for heating a space of a building that is to be temperature controlled by the boiler, wherein the boiler including a burner, the method comprising:

receiving a call for heat that is based on an air temperature sensed in the space of the building;

firing the burner based on the call for heat;

while firing the burner, monitoring over time a temperature difference between a first boiler temperature and a second boiler temperature, the first boiler temperature being measured proximate a water outlet of the boiler and the second boiler temperature being measured proximate a water return of the boiler;

if the temperature difference exceeds a threshold, shutting off the burner,

wherein the first and second boiler temperatures are indicative of the temperature of the boiler fluid proximate a water outlet and proximate a water return, respectively; and

monitoring a temperature deviation between the first boiler temperature and a heating temperature profile that represents an expected temperature response of the first boiler temperature over time to the burner firing, and if the temperature deviation exceeds an allowable deviation, shutting off the burner.