DIY Home Improvement Forum banner

Heil CA3018QKA1 Won't start

1K views 6 replies 2 participants last post by  Doc Holliday 
#1 ·
I have a Heil CA3018QKA1 unit and an Armstrong furnace. I just installed a Honeywell RTH221 stat because when I went to start the cooling system yesterday it did not start and I was assuming the old round Honeywell stat was bad. With cool on and auto, when I moved the temp dial the mercury switch did not spark as is normally does indicating power.
I place the wires in the stat as follows:
Yellow - Y
Red - RC
Blue - R
Green - G
White - W

Originally I had R/RC jumpered with the Red wire going to it. Nothing worked. I removed the jumper and placed Blue to R and Red to RC. Now when I go to "FAN" the furnace kicks on but does not in Auto with the stat set to 90deg. I still have no response from the Heil unit. I thought there may be a compressor reset but this unit appears to have none. Any ideas?
 
#2 · (Edited)
Not sure what blue to R is. What's blue hooked to inside of the furnace? What was the old wiring in the old stat?

R-24 volts from furnace hooked to R in the stat. Usually red.
Y-cool. Either blue or yellow. Need to check inside of furnace to see unless you know which wire was connected to Y on the old stat.
G-fan. Usually green
W-heat. White

You don't need a common wire on an old stat but if the new one is digital and you do not have batteries then common will need to be hooked up in the furnace and in the stat. Common will be labeled C, not R. R on the new stat is for the power to come in so again, that blue wire is out of place there.
 
#4 ·
It has batteries. I pulled blue and tapped it. Jumpered R/RH with red. Breaker on still nothing. No 24v going to the HVAC. There is a transformer in the furnace with blue going to the red terminal (top right of two columns of three) and red is on the C terminal (Bottom right) I checked at the junction where the white and red exit the furnace and go to the HVAC, no 24v. and still no response to the stat.
 
#5 ·
It's easiest for us if we can see what you are seeing. Can you take some pics of all wiring, inside the furnace, the transformer wiring and the stat and post them here?

Does your furnace have a door switch on it? It would need to be pushed in for power to get to the transformer if so. Need to check voltage going into the tranny as well as out. If nothing out than tranny is bad.
 
#7 ·
Certainly. Check your pm's but then again you need to have a minimum of 20 posts to use that feature. Check the rest of the forum out, see if you can't assist someone else or just clown around down in off topic section to get your post count up.

Once you're at 20 you can use the Private Messaging, pm. Sorry, but I won't post my e-mail publicly.

Might be best to take digital pics, upload them to whichever photo account you use and then post them here. Also more hvac techs will be able to see it and help if posted here.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top