Taco I series question.

JimmyJam

Having trouble starting the I series reset control system we installed today. Outdoor sensor is reading 12K with long 18/2 run connected but is reading resistance of 23.9K without leads connected. How can this be? I find it hard to believe there is a short in 18/2 but what else can it be? The valve has a steady green light but will not modulate open.
Any ideas? Thanks!

Abe Fanning

Taco I series

JimmyJam,

Just curious, did you take a resistance reading of just the 18/2 wire (without the sensor attached)?

Maybe it is shorted like you say.

Abe.

JimmyJam

We found the problem to be in the wiring terminal block in the outdoor enclosure.

hydronicsmike

makes no sense to me...

...If Resistance is 23.9K, then it is not a short circuit, or else it would read 0 resistance.

The Outdoor Sensor should be a 10K Thermistor (if I am not mistaken) and that would reference an Outdoor Temperature of roughly 43°F.

Anyways, I am glad you figured out that something was wrong and it is working fine now, but it certainly was not a short circuit.

If a problem with an Outdoor Sensor is encountered, in most cases, it is caused because another sensor was wired to the same terminals inside of the Outdoor Sensor Enclosure. The Sensor is built in and cannot be seen (easily) and no other sensor is required inside of it. Simply connect the wires from the Control (on the valve) to the two terminals inside of the Enclosure.

Hope this helps.

Regards,

Mike