Smart Thermostat /Dumb Installer


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Old 04-24-17, 06:06 AM
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Smart Thermostat /Dumb Installer

Hi all and thanks in advance. I've seen similar posts to mine and your expert walk through gave me some confidence I could complete this with your help. Skill level zero here when it comes to electricity.

I'm installing an Ecobee 3 thermostat to replace a Honeywell thermostat which ran off batteries, so no "C wire" at the thermostat. Only the Red, Green and Yellow were available as the rest were twisted around the cord and shoved back in the wall not easily accessible.

I'm attaching the Ecobee to a Ruud Achiever Air handler (I have a separate boiler/ oil furnace for heat attached to a Nest Thermostat). My heating thermostat is downstairs and my AC thermostat is upstairs, so you can imagine the house is freezing downstairs in summer since the thermostat is upstairs, hence my interest in the Ecobee with remote sensor capability.

I'm trying to us the Power Extender Kit (PEK) that came with the Ecobee but am not sure which wires to insert into the PEK.
1. Which is the C wire in my picture? Is it twisted to the white wire in [D]
2. If I have no heat then why is the brown connected to the white wire on the thermostat cable, which oddly is not available at the thermostat?
3. Is the safety cut-off switch wired correctly in the first place (not my handy work), in the picture. [A] yellow to thermostat/ black to safety cutoff switch and [B] reddish/orange to ?? and black to safety cutoff switch.

In short what gets plugged into the PEK and what gets twisted to the terminals on the PEK?





Thanks in advance.
 
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Old 04-24-17, 11:12 AM
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Welcome to the forums.... useful.

A and B are connected to a float that will open the yellow (Y) if the pan overfills with water.

If you have extra wires in the cable..... USE them !

The red wire at B and the white wire at D should go to to a two wire cable and then out to the A/C condensor.

The brown and white connection at D is the common C connection.
Pick a spare wire in the existing cable and use that.
 
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Old 04-24-17, 12:25 PM
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I agree with Pete. You have extra wires in the thermostat bundle, why not use them. Usually the installer leaves enough excess thermostat wire so you should be able to pull the cable out some more near the thermostat and gain access to the unused wires. Connect one to the C terminal on the new thermostat and the other end to the C terminal on the air handler terminal strip. If, for some reason, you don't have a C terminal at the air handler, connect the new "C" wire to the chassis of the air handler.
 
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Old 04-24-17, 12:55 PM
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Thanks and I'm Useless until I sort it out

So if I understand correctly, skip the PEK and twist one of the spare wires (not used but in the bundle of thermostat wires in the AC housing) with the wires in [D] and plug the corresponding end into the C at the thermostat?

Sounds simple enough.

Thanks in advance and when I get the time, I'll report back if that is indeed what I need to do. Thanks again.
 
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Old 04-24-17, 01:02 PM
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If you have a multimeter, you can double check to ensure that (D) is the common. Set your multimeter to AC volts and measure between D and whatever wire the Red thermostat wire is connected to. You should measure ~24VAC. As a second check, check voltage between D and the air handler chassis. You should measure 0VAC.
 
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Old 04-24-17, 02:21 PM
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I may be out of line but that's the funniest title to a thread I have seen
 
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Old 04-24-17, 02:39 PM
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Thanks again

1. I do have a multimeter and will test the voltage, I saw a Youtube video of how to locate a C-wire at the thermostat and when I initially did this holding one end to red (at thermostat) and the other to yellow or green (at the thermostat) and I saw voltage for both - I'll double check as this confounded me.

2. Handyone, no worries - I'm humble and if I can't get it right I can at least laugh at myself (after a little cursing of course).

This is a great site and very helpful thread. Unfortunately to access my AC I need to pull a wall panel off as this was added to an older home so it's not as easy as running to the basement or closet. I'll keep you in the loop.
 
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Old 04-24-17, 03:28 PM
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You cannot measure for C in that manner. You cannot properly measure for C at the stat end.
You will read 24vac between R and G, R and Y, R and W, etc.
 
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Old 04-25-17, 07:26 AM
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Thumbs up Thanks Everyone!!

A round of beers are in order. Your expert direction helped me out, avoided the PEK. Pulled the brown wire from the tsat cable through the wall at the tsat then unwound the brown from the bundle inside the air handler and stripped the end. Twisted it to the two wires in [D]. {note all circuits were OFF - not completely useless}. Hooked up the brown at the tstat into the C plug of the Ecobee and the corresponding R, Y, and G at their points in the Ecobee. Flipped the circuit breaker back on, flipped the switch at the air handler and the little bugger fired up. Closed up the air handler and tested the AC. All is good!

Thanks again - first time using this site and not my last if the rest of the forums have knowledgable help like in this one.

Is there a feedback mechanism built into this to give a thumbs up/thanks to those who have helped?
 
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Old 04-25-17, 07:29 AM
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Useless (we're going to change your name to Useful), glad to hear that everything worked out well for you. I'm not aware of any feedback mechanism, just your replying to let us know that go got it up and running is thanks enough. Glad we were able to assist.
 
 

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