what does this thermostat sensor in this picture exactly do?

[onesickcrx]

Sensor #4 I ordered every sensor brand new since I am installing it in my new thermostat housing the only old one is #4 since its discontinued... I broke it soon as it got snug /ubbthreads/images/graemlins/mad.gif

I need to figure out what its exact job is because I may not need it I hope...

 

[brisvr4]

That's the emergency sensor (not the correct name)
It will turn on both fans on full if you start to overheat. I hooked the wire for mine into a power/economy switch so I cna flick the fans on manually if I need to. If you earth it you will see what I mean.

 

[onesickcrx]

Quoting brisvr4:
That's the emergency sensor (not the correct name)
It will turn on both fans on full if you start to overheat. I hooked the wire for mine into a power/economy switch so I cna flick the fans on manually if I need to. If you earth it you will see what I mean.




So its just a safety switch to turn on all the fans incase of a overheating problem. Not something I need but wouldn't hurt to have a switch hooked up to activated all the fans manually is what your saying... correct?

 

[toybreaker]

It will also signal the hvac controller to cut the power to the a/c clutch, effectively disabling the a/c system for the duration that the blue/black wire "sees" ground.

 

[onesickcrx]

^ thats good to know since I do have a/c