I've been having problems with a hot water circulation system. It worked last winter and is connected to a wall mounted thermostat for radiant heating. When I multimeter the switching relay I don't have low voltage across the wires that connect to the thermostat (T and T when checked against each other and also if checked against ground.
In the relay box the labels on the screws on the right side of the picture are:
2 - 2
1
3 4
If I meter 1 to 2 or 1 to 4 I get 120 V. If I meter 2 to 3 I get zero volts.
Based on the relay schematic, shouldn't I always have 20V at T? If the thermostat is open wouldn't T to T give 20V and if the thermostat was closed wouldn't I get zero volts? Since I'm not getting either does that mean the transformer is dead? Any other thoughts?
In the relay box the labels on the screws on the right side of the picture are:
2 - 2
1
3 4
If I meter 1 to 2 or 1 to 4 I get 120 V. If I meter 2 to 3 I get zero volts.
Based on the relay schematic, shouldn't I always have 20V at T? If the thermostat is open wouldn't T to T give 20V and if the thermostat was closed wouldn't I get zero volts? Since I'm not getting either does that mean the transformer is dead? Any other thoughts?
