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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22541
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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LUX 1500 thermostat has every option lit up on panel. Air conditioning

This answer was rated:

LUX 1500 thermostat has every option lit up on panel. Air conditioning will not come on. Fan will. Cannot get the panel to respond otherwise. Breaker not flipped, new batteries.

any idea?


I would like to eliminate something first if you dont mind a hands on test..?

Customer: replied 5 years ago.



Remove top section from wall.

Underneath you will see thermostat wire terminals. They are labeled R,G,Y,W...we want to take a paper clip and shape it in a U..touch one end to R and the other to G thus connecting them...tell me if blower starts in furnace.

Customer: replied 5 years ago.

not wanting to start the furnace. i can run the fan/blower for the airconditioner, but the outside unit will not respond.

still want to run this same test? Should i then have the panel set up for heat and blower?


Customer: replied 5 years ago.

my terminals are labeled





The R and G will not start the only starts the blower IN the furnace.

So you are saying the indoor blower turns on but not the outdoor section?

Customer: replied 5 years ago.



and the panel to set the temp has every option lit up.

Ok, sorry to drag this out...when you say every option lit up I picture every icon available lit whether being used or not.

Is this the case or does the thermostat appear normal with the proper icons lit?

Customer: replied 5 years ago.
yes, every option lit up whether being used or not
Thank you...lets do the same test but with R and Y...

tell me if outdoor ac unit turns on.

Customer: replied 5 years ago.

stand by


Will do...

Customer: replied 5 years ago.

RH or RC and Y





Rh and Rc are joined so either, but use Rc..and Y
Customer: replied 5 years ago.

yes, blower started


that good?

To be exact the "outdoor blower" started?

Customer: replied 5 years ago.
yes, outdoor unit turns on.

Now we know the system is ok but the thermostat is acting up.

Put the batteries in backwards for 15 seconds..then install correctly and tell me fault remains.

Customer: replied 5 years ago.



fault remains

Then thermostat is defective.

Do you wish to have cooling until you can replace?

Customer: replied 5 years ago.



i think the home depot down the street is open until 10.


paper clip in place until then?


or Not...

You can take the R, G and Y wires and twist them together.

The R = 24v
The G = indoor blower
The Y = outdoor ac unit

then if it were heat you wanted it would be R and W as W is heat terminal.

I wish you luck!

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