Vision Pro IAQ Emergency LED Operation?

[rjp]

Ok, I now have the equipment failure LED functional on my Vision PRO IAQ with EIM system. That was connecting the York X/L to the EIM's L input. Doing so revealed the existence of the Thermostat's Red LED behind the white plastic case, top right.

Now I read that the Emergency Heat is supposed to illuminate this or a similar LED. But it doesn't. I do get "Aux Heat On" displayed on the LCD instead of simply "Heat On".

Does the Vision PRO IAQ thermostat inherently operate the LED under emergency heat or is there some other wiring necessary?

[beenthere]

I don't know why they say that.
It doesn't come on.

[motoguy128]

I thought the red LED was a myth. I figured it was referenced in the manual to confuse DIY's that purchased their IAQ online, forcing them to contact a Pro to complete the installation. After the pro failed to find the solution, they would be instructed by Honeywell to attend a overpriced training class.... thus completing the cycle.

At least the red LED apparently exists and has some useful function.

So when there is an equipment failure, does the IAQ automatically switch to EM heat???

[beenthere]

Depends on how its set up.

On a dual fuel, set to use lock out temps.
If the temp is above the furnace lock out, your out of heat if the HP fails.
Unless you manually switch it to emergency heat.

[rjp]

My heat pump does turn on the emergency heat on failure. Problem was I won't know it most of the time. Now I can see the LED indicating the heat pump's down. By further logic I can assume the emergency heat is on if heat is being produced.

[jddilligaff37]

it takes additional wiring at least on lennox. out door units, will have a L on the circuit board for light on t stat i never wire it up it is not critical for proper operation