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Discussion Starter · #1 · (Edited)
Hello,

I really need to know how to connect the wires for my central AC unit to my electric furnace so that it can be turned on by the thermostat.

Please see the following pictures for a quick summary of what i need to know to make this work, and/or read on for full description. It's starting to get pretty hot in here (30c) and i have a 6mth old so i really want to make this work as soon as possible.

Thermostat pic:
Thermostat Pic on Photobucket

Furnace pic:
Furnace Pic on Photobucket

Long story:

our furnace died this winter... so we replaced it with a brand new one, including a new thermostat. Before the electrician got here, i installed the thermostat myself to save money, and i had also undone the old furnace connections in the basement myself again to save time and therefore money.

However, i did not have the clarity to take pics of how the wires were connected before, and the electrician i got to come over is an acquaintance of an acquaintance of an... etc.... so i got this hooked up SUPER cheap, but he told me that without the pic from the old furnace, he was not sure how to connect the AC unit because he's not an HVAC electrician guy... if that makes any sense, and just left it like that.

So now summer is here and it`s really warm here. I would really like to connect my AC unit to the furnace so that the thermostat can control it by starting both the AC unit, and the furnace fan.

The brown wire you see on the right of the Furnace pic above, rides along the condensation tube and goes out to the central AC unit outside. And since the guy plugged in all the other wires except the Y one, i figured i need to connect those 2 together... the only problem i have is that the brown wire has 2 wires inside it (one black, one white) and yet the furnace has 1 spot to connect to UNDER the Y... i did notice the jumper to the right, but i don'T want to blow anything up either.

So if you could direct me as to how to make this final connection, i would really appreciate it.

Thanks in advance!
 

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Discussion Starter · #6 · (Edited)
hey,

please review the following (i have plugged the wires in as described), and yet nothing happens when the thermostat turns on... and the "cool" sign flashes on my thermostat when it engages... ? both the furnace and the AC breakers are on on the main panel, and the breaker directly on the AC unit outside is also set to ON...

actually the cool sign is no longer flashing (stopped flashing after 5 minutes and i heard the thermostat engage)... but still, nothing happens :(((((

New Wiring Setup at Furnace...

on another note, please note that the wiring described earlier is wrong for the Rs... on the therm they are, from left to right respectively:
Rh
Rc
 

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Discussion Starter · #7 · (Edited)
and also, here is the manual for my thermostat... does the cooling power supply have anything to do with my problem? Note that i originally removed the jumper between Rh and Rc since the manual said to remove it for a 5 wire system, and i have a 5 wire system... was i not supposed to do this?

RTH2520B User Manual
 

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Discussion Starter · #9 · (Edited)
uhm... you posted my image with no comments? this is currently how it's hooked up yes. And nothing happens... :(

i basically plugged in the black wire that goes to the AC where the arrow labeled BLCK points, and the white wire going to the AC where the arrow labeled WHIE points (there is also a red wire connected there)...
 

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looks like the furnace is wired wrong...disconnect stat wires on furnace control and let me see it ....gas ,oil or electric heat... 1 or 2 transformers...I think its wired wrong...
 

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Discussion Starter · #13 · (Edited)
looks like the furnace is wired wrong...disconnect stat wires on furnace control and let me see it ....gas ,oil or electric heat... 1 or 2 transformers...I think its wired wrong...
uhm... you want me to do what exactly? disconnect all the wires from the connectors, and take a picture of that? just the wires coming from the thermo or all all the wires?

i can also take a picture of the furnace information sheet posted on the front of it for the other information?

electric furnace
central air pulsated (fan)
?? 1 transformer ?? not sure what that means... theres a breaker on the furnace (small reset button), two on the wall board (ac and furnace, both with dual breakers for both), and one big breaker box outside for the AC...
 

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uhm... you want me to do what exactly? disconnect all the wires from the connectors, and take a picture of that? just the wires coming from the thermo or all all the wires?

i can also take a picture of the furnace information sheet posted on the front of it for the other information?
yep... disconnect thermostat wires at furnace control.....why is red on common side ...from stat
 

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Discussion Starter · #16 ·
ok... all the stat wires are DCd from the furnace. Here are the pics i took... i tried different angles and closeups but just let me know if you need a different angle.

I have left the wires going to the AC connected though...

(sorry photobucket taking forever to upload... i`ve gone one in there... more to come.)


thanks again for your help i really appreciate it!
 

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ok... all the stat wires are DCd from the furnace. Here are the pics i took... i tried different angles and closeups but just let me know if you need a different angle.

I have left the wires going to the AC connected though...

(sorry photobucket taking forever to upload... i`ve gone one in there... more to come.)


thanks again for your help i really appreciate it!
hate to be a pia but let me see the ends of thermostats wires ....
 

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ok really don't think you need 5 wires..don't do electric furnaces but it shoulden't matter...put red to red.... put white to w1.... put orange to y1 put green to g...then lets go back to stat base...just keep in mind you may have blown a fuse somewhere.....and stat has a time delay up to 5 min...
 
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