Patent ID: 8904971

Claim:
A method of controlling combustion of a gas appliance, comprising the steps of: a) reading a first burning data in a database; b) burning gas according to the first burning data; c) obtaining a burning efficiency of the gas appliance; and d) comparing the burning efficiency with a predetermined value, and repeating the step b to the step d when the burning efficiency is higher than the value, or reading a second burning data in the database and burning gas according to the second burning data when the burning efficiency is lower than the value; wherein the first burning data includes a first water supply index that a flow rate of water to be heated is adjusted to meet the first water supply index in the step b; wherein the second burning data includes a second water supply index that the flow rate of water to be heated is adjusted to meet the second water supply index in the step d; wherein the burning efficiency is calculated from a concentration of carbon dioxide after burning.