No Heat

Thermostat Interface Control Support

No Heat

Postby lwsisson » Mon Feb 06, 2012 7:05 pm

My Thermostat 3M50 does not turn the Heat on. I have good Wi-Fi connectivity. The C-Wire is fine. I have tested the following wire couples and all have atleast 24 volts. Red-Yellow, Red-White, Red-Green and Red-Cwire. The fan turns on when I set the fan to "on", however, it blows cold. The fan does not come on in "Auto". I have a Lennox 15GCSXAV-60-110 X-230 Package Unit. I have hooked up my old thermostat and the heat works fine.
lwsisson
 
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Re: No Heat

Postby blaine » Mon Feb 06, 2012 8:42 pm

It is very likely you have it connected wrong. If the red wire was connected to the RH and RC on the old thermostat it is NOT the C wire. There is no color code. What letters did you connect from the old thermostat to the new thermostat? If you have conventional heat and cool you should have the following:
R to RC and RH connected together for 24VAC switching power (do not connect to C)
W to W for heat
Y to Y for cool
G to G for fan
C to C for 24VAC common

Notice that is 5 wires not 4, you are missing a wire (probably the C) as many systems do not bring that up to the thermostat.
Get you thermostat connected first and then find and connect the C wire. Go to "powering your thermostat" this forum.

With heat and cool off there should be;
24VAC between R: and W or Y or G.

When you find and connect the C wire, there should be;
0V between C; and R or Y or G
24VAC between C and R with the heat on or off.
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Re: No Heat

Postby lwsisson » Tue Feb 07, 2012 3:25 pm

I have a blue c-wire and it seems to be working fine. I get a WiFi connection.

I have attached a picture of my wiring. I used page 14 in the install manual for the wiring.

The old thermostat used:
R to RC and RH
W to W
Y to Y
G to G
BLUE IS NEW and was not used on the old thermostat.

There is 24 volt between R: and W, Y or G.
There is 0 volt between Blue(c-wire) and W, Y, G.
There is 24 volt between R and Blue
Attachments
thermostat_wiring (Small).JPG
Picture of Wiring
thermostat_wiring (Small).JPG (48.19 KiB) Viewed 309 times
lwsisson
 
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Re: No Heat

Postby blaine » Tue Feb 07, 2012 11:36 pm

The white wire is connected to the wrong terminal, it should be connected to W not W2.
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