My heating system is floor radiant heating with 6 zones. 5 themostat are honeywell and 1 is white rogers brand. All are simple 2 wire / mercury type with anticipator and set all at .4
I notice that time to time in the master bed room when the temperature reach the thermostat set point 21c the furnance still keep on heating and cause the furnance temperature to exceed it max setpoint 40c + 5c. In this case the furnance will then shut off. But since there is still call for heat by the thermostat in the master bed rm, the furnance will between 1 to 5 mins restart again.
1. Does this mean the anticipator is set incorrectly in master bed room thermostat? Originally it was set at .4 and now I move it to .3 to give it a try. Should all same type of thermostat anticipator be set at a same number or each has to be check and set on there own setting?
2. Or the thermostat is bad?
3. Or time to change to a more accurate digital type thermostat?
ps. I know using amp meter there is a way to figure out the correct anticipator setting. Pls advice the procedure of how to check that and were to put the 2 metal tip of the meter on the thermostat.