Patent ID: 8545214

Claim:
A method of operating a variable speed combustion blower of a combustion appliance that has five or more different firing rates, including a minimum firing rate, a maximum firing rate and at least three intermediate firing rates between the minimum firing rate and the maximum firing rate, each of the five or more firing rates having different corresponding combustion blower speeds, the combustion appliance further having a first pressure switch and a second pressure switch, the method comprising: changing the blower speed of the variable speed combustion blower until the first pressure switch changes state; determining a first blower speed that is related to when the first pressure switch changes state, the first blower speed corresponding to the minimum firing rate of the combustion appliance; changing the blower speed of the variable speed combustion blower until the second pressure switch changes state; determining a second blower speed that is related to when the second pressure switch changes state, the second blower speed corresponding to the maximum firing rate of the combustion appliance; determining a third blower speed that corresponds to a first intermediate firing rate of the combustion appliance by interpolating between the first blower speed and the second blower speed; determining a fourth blower speed that corresponds to a second intermediate firing rate of the combustion appliance by interpolating between the first blower speed and the second blower speed; and determining a fifth blower speed that corresponds to a third intermediate firing rate of the combustion appliance by interpolating between the first blower speed and the second blower speed.