Heat not reponding to thermostats

shoby1

Looking for help. My heater is not responding to the thermostats. I have oil heat, boiler is up to temperature, I have hot water, I have a Taco SR506-2 (6 zone relay) which the power indicator light is on, fuse is good, wires are all tight, boiler does activate when calling for hot water but not heat. I did check the batteries in the thermostats. The indicator lights on the Taco do not light for heat when turning up the thermostats. Any help would be greatly appreciated.

CMadatMe

Two Things

Is the priority switch on the zone control turned off? Do you have wires going from XX on the zone control to TT on the boilers aquastat.

shoby1

thanks for the response

yes, the priority is switched to off and there are wires going from xx to tt

earl burnermann

check control and thermostat

If you jump out the low voltage wires that are used to turn on the circulator in the switching relay control, and it works then you have a problem with either your wiring or your thermostat. If the circ comes on when you jump out the thermostat wires in the switching relay then it's time to try the thermostat. Jump out the w and r wires at your themostat. If the circ comes on it's a problem with the thermostat. Is the thermostat set to heat? or is it set to off. Has to be set to heat if the thermostat is a heating cooling thermostat. If the circ does not come on when you jump out the w and r wires at the thermostat you have a problem with your thermostat wires.

shoby1

thanks for the response

Okay, I jumped the red and white wires, at the relay and nothing, at the thermostats, nothing. Power indicator light, for Taco, is still on though.





There are 5 thermostats in the house, all set to heat and all set above room temp. Not one zone indicator light is lit. The only way I'm getting heat to circulate is by opening the check valves. I did try jumping the black power wire for the circulators, they do work. Could the Taco box have gone bad? Installed in 2003. Looking inside the taco box, everything still looks new except that there's a transformer of some kind on the bottom that looks worn, almost blackish.

lchmb

fuse

I believe there is a 1 amp fuse, have you checked that? The other thing to check is the transformer, is it putting out 24 volts?

billtwocase

ditto

check for power out of your step down. Unless I need to prioritize for some reason, I personally don't use them. They are only a light show. JMHO