Why won’t my boiler(s) fire? I wired the control with power and connected my boiler to it but it is not turning on the boiler(s). The boiler does fire when I press the test button.

Classic series tekmar controls require a call for heat, or demand, to be applied to the control. Check the display to see if a boiler demand is present, you may not have provided a demand to the control. Use the building thermostat, or end switches from zone valves or zone pump relays to apply either 24 V (ac) power to the demand terminals on the control.