Monday, March 10, 2014

Thermostat Wiring Help Illustrations Included



I recently purchased a Climatouch CT03TS32H programmable thermostat. It's a pretty nice unit that really does a lot more right now than I need, but I'd like to go ahead and hook it up before I start messing with the humidistat and ext temp input.
I'd appreciate if someone in the know could help make sure I'm hooking the wires up to the right inputs.
Furnace: Lennox
AC: Lennox
Here is the Climatouch units inputs. I had to write in the letters so that it was easier for everyone to read.
http://img.photobucket.com/albums/v638/BQuicksilver/Climatouch.jpg
Here is the wiring on our current thermostat. It looks like I have 4 wires (R, W, G, Y) and one wire that connects RH and RC.
http://img.photobucket.com/albums/v638/BQuicksilver/Sears.jpg
I was thinking this would be my layout on the new thermostat:
- R to RC and RH (same as old unit)
- G to G (same as old unit)
- W to W1 (?) - is this for the heater
- Y to Y1 (?) - is this for the AC compressor

You have it right. Turn the power off first so you dont short the transformer.
R is power so you need the jumper from RC too RH
G is fan W is heat and Y is cool.
Be sure and read all the papers that came with it and be sure and set it like it said . keep the paper works

Well, I wired it up, and the unit looked wonderful. I was setting the date/time and then it started making a clicking sound about 2x/sec and the furnace seemed to be making an attempt at turning on. Next thing I know it's completely dead.
I fear the worst, what happened?

I did come across this in the troubleshooting section, but it was over my head. Maybe there is something here?
Issue: Thermostat appears normal until the screen becomes blank when the compressor or heating system turns on
Solution: You need to connect the C wire. 4 wire systems will not function unless the heat and compressor contactors can supply enough current to power the thermostat with only 4 wires. If you cannot hook up the C wire another possible solution is to connect two 100ohm 10watt resistors in the HVAC room, one between Y and C, and the second between W2 and C.

Sounds like you got a power stealing t=stat...
You will need to pull another wire or maybe got one behind the wall? And wire C at the t-stat and furnace.
Otherwise, if you can't do the wire, then go to radio shack and get the resister (Unless they provide them with the t-stat?) Install that as they said in the manual.

There are a couple more wires stuffed behind the thermostat that were not being used, but I'm not sure ID which one is C.

The Climatouch automated tech support line described my problem verbatim and said that C needs connected.
The unused wires behind my thermostat aren't marked, so it isn't as easy as ID'ing the blue wire. Is there a way to ID by voltage?
My furnace has an old unused humidifier, so I assume at least one of the two wires is for it.

Pull a wire.. (Blue) out of the wall, and wire that to C.
Then go down to the furnace, and you should have blue wire hanging there or wrapped up. tie that to C on the board..
Make sure you turn off power when do this.

I did find a wire with blue cloth insulation pushed back into the wall, and wired it to the blue wire from the furnace and C terminal, but the thermostat still did nothing after I kicked the breaker back on.
Any ideas? I feel like I need to have my voltmeter and wire tracer out, but I'm really not sure what to look for.

The wire tracer confirmed that I have continuity from furnace to thermostat.
I did notice that the furnace had a blue AND dark blue wire coming from it. Neither made the thermostat wake up.
I took a voltmeter and no voltage was registered on any of the wires coming into the thermostat, including red and blue wires.
Ideas? It's getting cold here.
I'm assuming the issue is a lack of power to the unit, but have no idea what the root of this issue might be.

Update again.
Power 15A was getting to furnace, pilot light (i think that's the term - the small blue flame) was running inside the furnace so I assume it's not a gas issue (Lennox Furnace). I could not get any voltage on the small wires coming out of the furnace.
I assume something in the transformer gave up...I assume.
Does anyone have some high yield advice for what to look at now?

Transformer had 120in, nothing out and stunk like it was fried.
I'm not really sure what I did that fried it. I wired with power off, and when it fired up there was no drama until the furnace tried to kick on...then the clicking started.

Did you ring out the blue you used for common at the furnace at the tstat??? R to that blue gave you 24V??

Originally Posted by Ed Imeduc
Did you ring out the blue you used for common at the furnace at the tstat??? R to that blue gave you 24V??
I think the transformer was fried way before I ever found the blue wire. No juice was coming from either red or blue. I'm still not sure exactly why the transformer died.
Since nobody in town would sell one to a DIYer I just called an HVAC guy (friend of neighbor) and said to come over with one in hand. I'll probably get the inspection and double-check the wiring while he's here.
I couldn't sit in the cold and wait for one to show from EBay or wherever.

When you first wired up the t-stat, did you turn off the power?
if you got a burnt smell, you may of shorted out the transfromer.
Keep us posted on what the guy finds for you.

Well, we're up and running now.
I did turn off power before wiring, but the transformer was also fried.
The problem was that some of the 24V wires were connected improperly on the transformer side, so while I was conecting things to the correct color terminals everywhere, some of the wires weren't what they should have been per the color...notably Y and C. I believe this caused a transformer failure early on and then from that point nothing I did mattered without any power from the transformer. Somehow this wiring setup worked fine with the old Sears T-stat we had, but not with the new unit.
Problem solved, but I'm $133 poorer.

Well, It could of been worse... But glad to hear you are back up and running.

some of the wires weren't what they should have been per the color...notably Y and C. I believe this caused a transformer failure early on
Thats what got you. That Y is hot or the same as R when calling. So if it got near C then you have a dead short to the transformer

I ca not completely hook up my new Honeywell RTH5001B thermostat. The wires on the old thermostat are B,R,G,W2,Y,X and E. The spots on the new thermostat are Rc,R,Y,NOT USED,W and G. Can anyyone help? Thank You in advanced.

Originally Posted by ckhamm1976
I ca not completely hook up my new Honeywell RTH5001B thermostat.
I can't find that model #.
Is your system a heat pump?
What is the make and model of the old t-stat?






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