into the system this indicates that the burner is not functioning properly and the system will react accordingly e g in a set period of time shut down and lock out the burner 11 thereby requiring a manual reset the system could further encompass an annunciator even though none is specifically shown in fig1 the system of fig1 thus simply accomplishes an antirust mode of operation of the boiler heat exchanger 13 by ensuring that the water 14 is adequately and properly heated before the circulator pump 15 is energized to circulate the water through the heat exchanger means 20 the system also is capable of the safety functions of low water cut off and of shutting the system down if the burner is not providing adequate heat to the water 14 to raise the temperature of the water in a proper manner in fig2 a flow chart of the system is disclosed and is substantially self explanatory only brief comments will be provided the flow chart of fig2 starts when the flame is proved at 50 and a temperature is noted at 51 this defines the value of the temperature in the boiler water and assigns it the designation as tbw1 which is the temperature of the boiler water at a moment of time t1 this information is noted at 52 where it is fed to a decision block 53 the decision block compares the temperature of the boiler water to make sure that it is greater than the temperature of the boiler water set as a minimum if it is a 34 yes 34 output is provided at 54 to provide normal operation at 55 if the result of the decision is 34 no 34.